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ExaminerPrep › Question bank › IB Maths AA SL › Topic 3 Geometry and trigonometry

IB Maths Analysis & Approaches · Standard Level · Topic 3

Geometry and trigonometry

Original questions in the style of Papers 1 and 2, each with a full worked mark scheme. Tick questions to build a printable test. Topic 3 at Higher Level →

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Original questions in the style of each exam boardFull worked mark schemes with method and accuracy marksCreated by Evan Kotronis with AI assistanceUpdated 14 October 2026 · new questions added continuouslyFree access until 30 November 2026How every question is checked →

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1AASL3-q00013.1 Three-dimensional geometry Paper 1Easy7 marks

The points \(A\) and \(B\) have coordinates \((-1,\,4,\,2)\) and \((3,\,-2,\,14)\) respectively.

(a)

Find the distance \(AB\).

(2)
(b)

Find the coordinates of \(M\), the midpoint of \([AB]\).

(2)
(c)

The point \(C\) has coordinates \((3,\,k,\,2)\), where \(k\in\mathbb{R}\). Given that \(CM=7\), find the possible values of \(k\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\sqrt{(3-(-1))^{2}+(-2-4)^{2}+(14-2)^{2}}=\sqrt{16+36+144}\)(M1)
\(AB=14\)A1
(b)
\(\left(\dfrac{-1+3}{2},\,\dfrac{4+(-2)}{2},\,\dfrac{2+14}{2}\right)\)(M1)Award for at least two correct coordinates.
\(M(1,\,1,\,8)\)A1
(c)
\((3-1)^{2}+(k-1)^{2}+(2-8)^{2}=49\)M1FT from their \(M\).
\((k-1)^{2}=9\)A1
\(k=4\) or \(k=-2\)A1Both values required.

Answers: (a) \(14\) · (b) \(M(1,1,8)\) · (c) \(k=4\) or \(k=-2\)

2AASL3-q00023.1 Three-dimensional geometry Paper 1Easy7 marks
8 cm3 cm
Diagram not to scale

A toy is made from a solid right circular cone joined to a solid hemisphere. The cone and the hemisphere have a common circular face of radius \(3\) cm, and the height of the cone is \(8\) cm, as shown in the diagram.

(a)

Find the volume of the toy. Give your answer in the form \(k\pi\text{ cm}^{3}\), where \(k\in\mathbb{Z}\).

(3)
(b)

Find the exact slant height of the cone.

(1)
(c)

Find the exact total surface area of the toy.

(3)
Show mark scheme
WorkingMarkNotes
(a)
cone: \(\dfrac{1}{3}\pi(3)^{2}(8)=24\pi\)(M1)
hemisphere: \(\dfrac{1}{2}\times\dfrac{4}{3}\pi(3)^{3}=18\pi\)(M1)
\(42\pi\text{ cm}^{3}\)A1
(b)
\(l=\sqrt{3^{2}+8^{2}}=\sqrt{73}\) cmA1
(c)
curved surface of cone \(=\pi(3)\sqrt{73}\)(M1)FT from their \(l\).
curved surface of hemisphere \(=2\pi(3)^{2}=18\pi\)(M1)Award M0 if the area of the common circular face, \(9\pi\), is added.
\(\left(3\sqrt{73}+18\right)\pi\text{ cm}^{2}\)A1Accept \(3\sqrt{73}\,\pi+18\pi\).

Answers: (a) \(42\pi\text{ cm}^{3}\) · (b) \(\sqrt{73}\) cm · (c) \(\left(3\sqrt{73}+18\right)\pi\text{ cm}^{2}\)

3AASL3-q00033.1 Three-dimensional geometry Paper 1Easy7 marks

The point \(A\) has coordinates \((-3,\,5,\,1)\). The point \(M(2,\,-1,\,4)\) is the midpoint of the line segment \([AB]\).

(a)

Find the coordinates of \(B\).

(2)
(b)

Find the exact length of \([AB]\), giving your answer in the form \(k\sqrt{70}\), where \(k\in\mathbb{Z}^{+}\).

(2)
(c)

The point \(C(0,\,0,\,c)\) lies on the \(z\)-axis and is equidistant from \(A\) and \(B\). Find the value of \(c\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{-3+x}{2}=2\), \(\dfrac{5+y}{2}=-1\), \(\dfrac{1+z}{2}=4\)(M1)Or \(B=2M-A\). Award for at least one correct equation.
\(B(7,\,-7,\,7)\)A1
(b)
\(\sqrt{10^{2}+(-12)^{2}+6^{2}}=\sqrt{280}\)(M1)FT from their \(B\). Or \(2\times AM=2\sqrt{70}\).
\(2\sqrt{70}\)A1
(c)
\((-3)^{2}+5^{2}+(1-c)^{2}=7^{2}+(-7)^{2}+(7-c)^{2}\)M1Equating \(CA^{2}\) and \(CB^{2}\) (or \(CA\) and \(CB\)). FT from their \(B\).
\(35-2c=147-14c\) or \(12c=112\)A1
\(c=\dfrac{28}{3}\)A1

Answers: (a) \(B(7,-7,7)\) · (b) \(2\sqrt{70}\) · (c) \(c=\dfrac{28}{3}\)

4AASL3-q00043.1 Three-dimensional geometry Paper 1Easy6 marks

A cylindrical container with internal radius \(6\) cm stands on a horizontal table and contains water. Metal balls, each a sphere of radius \(1.5\) cm, are dropped into the container. Every ball sinks and is completely covered by the water, and no water overflows.

(a)

Find the exact volume of one ball.

(2)
(b)

Twenty balls are dropped into the container. Show that the water level rises by \(2.5\) cm.

(2)
(c)

The container is emptied of balls, refilled to its original level, and \(n\) balls are dropped in. Find the least value of \(n\) for which the water level rises by at least \(3.7\) cm.

(2)
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WorkingMarkNotes
(a)
\(\dfrac{4}{3}\pi\left(\dfrac{3}{2}\right)^{3}=\dfrac{4}{3}\pi\times\dfrac{27}{8}\)(M1)
\(\dfrac{9\pi}{2}\text{ cm}^{3}\)A1
(b)
\(\pi(6)^{2}\times\text{rise}=20\times\dfrac{9\pi}{2}\)M1Equating the volume of a cylinder of water to the volume of the balls.
\(36\pi\times\text{rise}=90\pi\)A1
rise \(=2.5\) cmAG
(c)
\(n\times\dfrac{9\pi}{2}\ge36\pi\times3.7\Rightarrow n\ge\dfrac{133.2}{4.5}=29.6\)(M1)Or each ball raises the level by 0.125 cm.
\(n=30\)A1

Answers: (a) \(\dfrac{9\pi}{2}\text{ cm}^{3}\) · (c) \(n=30\)

5AASL3-q00183.2 Right-angled and non-right-angled trigonometry Paper 1Easy7 marks

Triangle \(ABC\) has a right angle at \(B\), \(AC=10\) cm and \(\sin B\hat{A}C=\dfrac{3}{5}\).

(a)

Write down the length of \([BC]\).

(1)
(b)

Find the length of \([AB]\).

(2)
(c)

The point \(D\) lies on \([AB]\) such that \(B\hat{D}C=45^{\circ}\). Find \(AD\).

(2)
(d)

Find the area of triangle \(ACD\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(BC=6\) cmA1
(b)
\(AB=\sqrt{10^{2}-6^{2}}\)(M1)Or \(10\cos B\hat{A}C\) with \(\cos B\hat{A}C=\dfrac{4}{5}\).
\(8\) cmA1
(c)
\(\tan45^{\circ}=\dfrac{6}{BD}\Rightarrow BD=6\)(M1)Triangle BDC is isosceles.
\(AD=2\) cmA1FT from (b).
(d)
\(\dfrac{1}{2}(AD)(BC)=\dfrac{1}{2}(2)(6)\)(M1)Or area \(ABC-\) area \(DBC=24-18\).
\(6\text{ cm}^{2}\)A1

Answers: (a) \(6\) cm · (b) \(8\) cm · (c) \(2\) cm · (d) \(6\text{ cm}^{2}\)

6AASL3-q00353.4 Radian measure, arcs and sectors Paper 1Easy5 marks

A sector of a circle has radius \(6\) cm and angle \(150^{\circ}\) at the centre.

(a)

Write down the angle of the sector in radians, as an exact multiple of \(\pi\).

(1)
(b)

Find the exact length of the arc of the sector.

(2)
(c)

Find the exact area of the sector.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{5\pi}{6}\)A1
(b)
\(6\times\dfrac{5\pi}{6}\)(M1)FT from (a). Or \(\dfrac{150}{360}\times2\pi(6)\).
\(5\pi\) cmA1
(c)
\(\dfrac{1}{2}(6)^{2}\left(\dfrac{5\pi}{6}\right)\)(M1)Or \(\dfrac{150}{360}\times\pi(6)^{2}\).
\(15\pi\text{ cm}^{2}\)A1

Answers: (a) \(\dfrac{5\pi}{6}\) · (b) \(5\pi\) cm · (c) \(15\pi\text{ cm}^{2}\)

7AASL3-q00373.4 Radian measure, arcs and sectors Paper 1Easy8 marks

The minute hand of a clock is \(12\) cm long and the hour hand is \(8\) cm long.

(a)

Find, in radians, the angle turned through by the minute hand in \(40\) minutes. Give your answer as an exact multiple of \(\pi\).

(1)
(b)

Find the exact distance travelled by the tip of the minute hand in \(40\) minutes.

(2)
(c)

Find the time, in minutes, that the minute hand takes to sweep out an area of \(60\pi\text{ cm}^{2}\).

(3)
(d)

Find the exact distance travelled by the tip of the hour hand in the same \(40\) minutes.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{40}{60}\times2\pi=\dfrac{4\pi}{3}\)A1
(b)
\(12\times\dfrac{4\pi}{3}\)(M1)FT from (a).
\(16\pi\) cmA1
(c)
\(\dfrac{1}{2}(12)^{2}\theta=60\pi\)(M1)Or the area swept per minute is \(\dfrac{144\pi}{60}=\dfrac{12\pi}{5}\).
\(\theta=\dfrac{5\pi}{6}\)(A1)
\(\dfrac{5\pi/6}{2\pi}\times60=25\) minutesA1Or \(60\pi\div\dfrac{12\pi}{5}=25\).
(d)
hour hand turns \(\dfrac{1}{12}\) of the minute hand’s angle: \(\dfrac{4\pi}{3}\div12=\dfrac{\pi}{9}\)(M1)Or \(\dfrac{40}{720}\times2\pi\).
\(\dfrac{8\pi}{9}\) cmA1

Answers: (a) \(\dfrac{4\pi}{3}\) · (b) \(16\pi\) cm · (c) \(25\) minutes · (d) \(\dfrac{8\pi}{9}\) cm

8AASL3-q00443.5 The unit circle and the ambiguous case Paper 1Easy6 marks
(a)(i)

Find the exact value of

\(\sin\dfrac{4\pi}{3}\);

(1)
(a)(ii)

\(\cos\dfrac{7\pi}{4}\);

(1)
(a)(iii)

\(\tan150^{\circ}\).

(1)
(b)(i)

It is given that \(\cos x=p\), where \(0\lt x\lt\dfrac{\pi}{2}\). Find, in terms of \(p\), an expression for

\(\cos(\pi-x)\);

(1)
(b)(ii)

\(\tan(\pi+x)\).

(2)
Show mark scheme
WorkingMarkNotes
(a)(i)
\(-\dfrac{\sqrt{3}}{2}\)A1
(a)(ii)
\(\dfrac{\sqrt{2}}{2}\)A1Accept \(\dfrac{1}{\sqrt{2}}\).
(a)(iii)
\(-\dfrac{\sqrt{3}}{3}\)A1Accept \(-\dfrac{1}{\sqrt{3}}\).
(b)(i)
\(-p\)A1
(b)(ii)
\(\tan(\pi+x)=\tan x\) and \(\sin x=\sqrt{1-p^{2}}\)(M1)Award for either; may be seen as a right-angled triangle with adjacent \(p\), hypotenuse 1.
\(\dfrac{\sqrt{1-p^{2}}}{p}\)A1Award A0 for \(\pm\).

Answers: (a)(i) \(-\dfrac{\sqrt{3}}{2}\) (ii) \(\dfrac{\sqrt{2}}{2}\) (iii) \(-\dfrac{\sqrt{3}}{3}\) · (b)(i) \(-p\) (ii) \(\dfrac{\sqrt{1-p^{2}}}{p}\)

9AASL3-q00473.5 The unit circle and the ambiguous case Paper 1Easy6 marks

Do not use a calculator in this question.

(a)

Show that \(\sin\dfrac{2\pi}{3}\cos\dfrac{\pi}{6}-\cos\dfrac{2\pi}{3}\sin\dfrac{\pi}{6}=1\).

(2)
(b)

Find the exact value of \(4\sin\left(-\dfrac{\pi}{3}\right)\cos\dfrac{5\pi}{4}\).

(2)
(c)

Find the exact value of \(2\cos330^{\circ}-\tan225^{\circ}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\sin\frac{2\pi}{3}=\frac{\sqrt3}{2}\), \(\cos\frac{\pi}{6}=\frac{\sqrt3}{2}\), \(\cos\frac{2\pi}{3}=-\frac12\), \(\sin\frac{\pi}{6}=\frac12\)A1Award for all four correct values.
\(\dfrac{3}{4}-\left(-\dfrac{1}{4}\right)\) or \(\dfrac34+\dfrac14\)A1
\(=1\)AG
(b)
\(\sin\left(-\frac{\pi}{3}\right)=-\frac{\sqrt3}{2}\) and \(\cos\frac{5\pi}{4}=-\frac{\sqrt2}{2}\)A1
\(\sqrt6\)A1Accept \(\sqrt{3}\sqrt{2}\) or \(\frac{4\sqrt6}{4}\).
(c)
\(\cos330^{\circ}=\frac{\sqrt3}{2}\) and \(\tan225^{\circ}=1\)A1
\(\sqrt3-1\)A1

Answers: (b) \(\sqrt6\) · (c) \(\sqrt3-1\)

10AASL3-q00563.6 Trigonometric identities Paper 1Easy6 marks

It is given that \(\sin\theta=\dfrac{1}{3}\), where \(\dfrac{\pi}{2}\lt\theta\lt\pi\).

(a)

Find the exact value of \(\cos\theta\).

(2)
(b)

Find the exact value of \(\tan\theta\).

(1)
(c)

Find the exact value of \(\sin2\theta\).

(2)
(d)

Find the exact value of \(\cos2\theta\).

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos^{2}\theta=1-\left(\dfrac{1}{3}\right)^{2}=\dfrac{8}{9}\)(M1)
\(\cos\theta=-\dfrac{2\sqrt{2}}{3}\)A1Must be negative. Award A0 for \(\pm\).
(b)
\(\tan\theta=\dfrac{\frac{1}{3}}{-\frac{2\sqrt{2}}{3}}=-\dfrac{\sqrt{2}}{4}\)A1Accept \(-\dfrac{1}{2\sqrt{2}}\). FT from (a).
(c)
\(2\left(\dfrac{1}{3}\right)\left(-\dfrac{2\sqrt{2}}{3}\right)\)(M1)
\(-\dfrac{4\sqrt{2}}{9}\)A1FT from (a).
(d)
\(1-2\left(\dfrac{1}{3}\right)^{2}=\dfrac{7}{9}\)A1

Answers: (a) \(-\dfrac{2\sqrt{2}}{3}\) · (b) \(-\dfrac{\sqrt{2}}{4}\) · (c) \(-\dfrac{4\sqrt{2}}{9}\) · (d) \(\dfrac{7}{9}\)

11AASL3-q00593.6 Trigonometric identities Paper 1Easy6 marks

It is given that \(\sin\theta=\dfrac{2}{5}\). The quadrant in which \(\theta\) lies is not known.

(a)

Find the possible values of \(\cos\theta\).

(2)
(b)

Find the possible values of \(\tan\theta\).

(2)
(c)

Explain why \(\cos2\theta\) has only one possible value, and find this value.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos^{2}\theta=1-\dfrac{4}{25}=\dfrac{21}{25}\)(M1)
\(\cos\theta=\pm\dfrac{\sqrt{21}}{5}\)A1Both signs needed.
(b)
\(\tan\theta=\dfrac{2/5}{\pm\sqrt{21}/5}\)(M1)
\(\pm\dfrac{2}{\sqrt{21}}\)A1Accept \(\pm\dfrac{2\sqrt{21}}{21}\).
(c)
\(\cos2\theta=1-2\sin^{2}\theta\) depends only on \(\sin\theta\) (not on the sign of \(\cos\theta\))R1
\(\dfrac{17}{25}\)A1

Answers: (a) \(\pm\frac{\sqrt{21}}{5}\) · (b) \(\pm\frac{2}{\sqrt{21}}\) · (c) \(\frac{17}{25}\)

12AASL3-q00643.6 Trigonometric identities Paper 1Easy7 marks
(a)

By using a double angle identity with \(\cos\dfrac{\pi}{6}\), show that \(\cos^{2}\dfrac{\pi}{12}=\dfrac{2+\sqrt3}{4}\).

(2)
(b)

Hence find the exact value of \(\cos\dfrac{\pi}{12}\), justifying your choice of sign.

(2)
(c)

Show that \(\left(\dfrac{\sqrt6+\sqrt2}{4}\right)^{2}=\dfrac{2+\sqrt3}{4}\).

(2)
(d)

Hence write down the exact value of \(\cos\dfrac{11\pi}{12}\), giving your answer in surd form without a nested root.

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos\dfrac{\pi}{6}=2\cos^{2}\dfrac{\pi}{12}-1\)M1
\(\dfrac{\sqrt3}{2}+1=2\cos^{2}\dfrac{\pi}{12}\)A1
\(\cos^{2}\dfrac{\pi}{12}=\dfrac{2+\sqrt3}{4}\)AG
(b)
\(\cos\dfrac{\pi}{12}=\dfrac{\sqrt{2+\sqrt3}}{2}\)A1
positive root since \(\dfrac{\pi}{12}\) is in the first quadrantR1
(c)
\(\dfrac{6+2\sqrt{12}+2}{16}\)M1
\(\dfrac{8+4\sqrt3}{16}\)A1
\(=\dfrac{2+\sqrt3}{4}\)AG
(d)
\(-\dfrac{\sqrt6+\sqrt2}{4}\)A1using \(\cos(\pi-x)=-\cos x\) and part (c). Award A0 for \(-\dfrac{\sqrt{2+\sqrt3}}{2}\) (nested root).

Answers: (b) \(\frac{\sqrt{2+\sqrt3}}{2}=\frac{\sqrt6+\sqrt2}{4}\) · (d) \(-\frac{\sqrt6+\sqrt2}{4}\)

13AASL3-q00673.7 Circular functions and their graphs Paper 1Easy7 marks

Let \(f(x)=\tan\left(x+\dfrac{\pi}{6}\right)\), for \(0\le x\le2\pi\).

(a)

Describe the transformation that maps the graph of \(y=\tan x\) onto the graph of \(y=f(x)\).

(1)
(b)

Write down the period of \(f\).

(1)
(c)

Find the equations of the vertical asymptotes of the graph of \(y=f(x)\).

(2)
(d)

Solve the equation \(f(x)=\sqrt{3}\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
translation by \(\dfrac{\pi}{6}\) in the negative \(x\)-directionA1Accept translation by \(\begin{pmatrix}-\frac{\pi}{6}\\0\end{pmatrix}\). Must be fully described.
(b)
\(\pi\)A1
(c)
\(x+\dfrac{\pi}{6}=\dfrac{\pi}{2},\ \dfrac{3\pi}{2}\)(M1)
\(x=\dfrac{\pi}{3}\) and \(x=\dfrac{4\pi}{3}\)A1Both equations required; award A0 if extra values are given.
(d)
\(x+\dfrac{\pi}{6}=\dfrac{\pi}{3}\), with \(\dfrac{\pi}{6}\le x+\dfrac{\pi}{6}\le\dfrac{13\pi}{6}\)(M1)
\(x=\dfrac{\pi}{6}\)A1
\(x=\dfrac{7\pi}{6}\)A1Award A0 if \(x=\dfrac{13\pi}{6}\) (outside the domain) is also given.

Answers: (a) translation \(\dfrac{\pi}{6}\) to the left · (b) \(\pi\) · (c) \(x=\dfrac{\pi}{3},\ x=\dfrac{4\pi}{3}\) · (d) \(\dfrac{\pi}{6},\ \dfrac{7\pi}{6}\)

14AASL3-q00693.7 Circular functions and their graphs Paper 1Easy7 marks

Let \(f(x)=5-3\sin\left(\dfrac{\pi x}{4}\right)\), for \(x\in\mathbb{R}\).

(a)

Write down the amplitude of \(f\).

(1)
(b)

Find the period of \(f\).

(2)
(c)

Find the range of \(f\).

(2)
(d)

Find the coordinates of the first maximum point of the graph of \(f\) for \(x\gt0\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(3\)A1Award A0 for \(-3\).
(b)
\(\dfrac{2\pi}{\pi/4}\)(M1)
\(8\)A1
(c)
\(5\pm3\)(M1)
\(2\le f(x)\le8\)A1Accept \([2,\,8]\).
(d)
\(\sin\left(\dfrac{\pi x}{4}\right)=-1\), so \(\dfrac{\pi x}{4}=\dfrac{3\pi}{2}\)(M1)
\((6,\,8)\)A1

Answers: (a) 3 · (b) 8 · (c) \(2\le f(x)\le8\) · (d) \((6,8)\)

15AASL3-q00723.7 Circular functions and their graphs Paper 1Easy7 marks

Let \(f(x)=4\sin\left(\dfrac{x}{3}\right)\) and \(g(x)=\tan2x\).

(a)

Describe the two transformations that map the graph of \(y=\sin x\) onto the graph of \(y=f(x)\).

(2)
(b)

Write down the amplitude and the period of \(f\).

(2)
(c)

Write down the period of \(g\).

(1)
(d)

Find the equations of the vertical asymptotes of the graph of \(y=g(x)\) for \(0\le x\le\pi\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
vertical stretch with scale factor \(4\)A1
horizontal stretch with scale factor \(3\)A1Accept either order. Award A0 for “factor 1/3”.
(b)
amplitude \(4\)A1
period \(6\pi\)A1
(c)
\(\dfrac{\pi}{2}\)A1
(d)
\(2x=\dfrac{\pi}{2},\ \dfrac{3\pi}{2}\)(M1)
\(x=\dfrac{\pi}{4}\) and \(x=\dfrac{3\pi}{4}\)A1Must be equations.

Answers: (b) amplitude 4, period \(6\pi\) · (c) \(\frac{\pi}{2}\) · (d) \(x=\frac{\pi}{4}\), \(x=\frac{3\pi}{4}\)

16AASL3-q00803.8 Trigonometric equations Paper 1Easy6 marks
(a)

Solve the equation \(2\cos x+1=0\), for \(0\le x\le2\pi\).

(3)
(b)

Hence solve the equation \(2\cos\left(x-\dfrac{\pi}{4}\right)+1=0\), for \(0\le x\le2\pi\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos x=-\dfrac{1}{2}\)(M1)
\(x=\dfrac{2\pi}{3}\)A1
\(x=\dfrac{4\pi}{3}\)A1Award A0 for answers in degrees.
(b)
\(x-\dfrac{\pi}{4}=\dfrac{2\pi}{3},\ \dfrac{4\pi}{3}\), with \(-\dfrac{\pi}{4}\le x-\dfrac{\pi}{4}\le\dfrac{7\pi}{4}\)(M1)FT from (a).
\(x=\dfrac{11\pi}{12}\)A1
\(x=\dfrac{19\pi}{12}\)A1Award A0 if extra values are given, e.g. \(-\dfrac{5\pi}{12}\) from \(-\dfrac{2\pi}{3}\), which is outside the interval.

Answers: (a) \(\dfrac{2\pi}{3},\ \dfrac{4\pi}{3}\) · (b) \(\dfrac{11\pi}{12},\ \dfrac{19\pi}{12}\)

17AASL3-q00823.8 Trigonometric equations Paper 1Easy7 marks
(a)

Solve the equation \(\tan2x=-1\), for \(0\le x\le\pi\).

(4)
(b)

Solve the equation \(\sin\left(\dfrac{x}{2}\right)=\dfrac{\sqrt3}{2}\), for \(0\le x\le4\pi\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(0\le2x\le2\pi\)(M1)Award for considering the extended interval.
\(2x=\dfrac{3\pi}{4}\)(A1)
\(2x=\dfrac{7\pi}{4}\)(A1)
\(x=\dfrac{3\pi}{8},\ \dfrac{7\pi}{8}\)A1
(b)
\(0\le\dfrac{x}{2}\le2\pi\); \(\dfrac{x}{2}=\dfrac{\pi}{3}\)(M1)
\(\dfrac{x}{2}=\dfrac{2\pi}{3}\)(A1)
\(x=\dfrac{2\pi}{3},\ \dfrac{4\pi}{3}\)A1

Answers: (a) \(\frac{3\pi}{8},\frac{7\pi}{8}\) · (b) \(\frac{2\pi}{3},\frac{4\pi}{3}\)

18AASL3-q00853.8 Trigonometric equations Paper 1Easy5 marks

Consider the equation \(\tan^{2}x+\left(1-\sqrt3\right)\tan x-\sqrt3=0\), for \(0\le x\le2\pi\).

(a)

Show that the equation can be written as \((\tan x+1)\left(\tan x-\sqrt3\right)=0\).

(1)
(b)

Hence solve the equation.

(4)
Show mark scheme
WorkingMarkNotes
(a)
\((\tan x+1)(\tan x-\sqrt3)=\tan^{2}x-\sqrt3\tan x+\tan x-\sqrt3\)A1
\(=\tan^{2}x+(1-\sqrt3)\tan x-\sqrt3\)AG
(b)
\(\tan x=-1\) or \(\tan x=\sqrt3\)(M1)
\(x=\dfrac{3\pi}{4},\ \dfrac{7\pi}{4}\)A1
\(x=\dfrac{\pi}{3}\)A1
\(x=\dfrac{4\pi}{3}\)A1

Answers: (b) \(\frac{\pi}{3},\frac{3\pi}{4},\frac{4\pi}{3},\frac{7\pi}{4}\)

19AASL3-q00053.1 Three-dimensional geometry Paper 1Medium8 marks

A solid hemisphere and a solid right circular cone both have base radius \(r\) cm. The total surface area of the hemisphere (including its flat face) is equal to the total surface area of the cone (including its base).

(a)

Show that the slant height of the cone is \(2r\) cm.

(2)
(b)

Find the exact height of the cone in terms of \(r\).

(1)
(c)

Show that \(\dfrac{\text{volume of the cone}}{\text{volume of the hemisphere}}=\dfrac{\sqrt{3}}{2}\).

(3)
(d)

Find the exact angle, in radians, between a slant edge of the cone and its base.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(2\pi r^{2}+\pi r^{2}=\pi r^{2}+\pi rl\)M1Hemisphere: curved 2πr² plus flat πr²; cone: base plus curved surface.
\(3\pi r^{2}-\pi r^{2}=\pi rl\) or \(2\pi r^{2}=\pi rl\)A1
\(l=2r\)AG
(b)
\(h=\sqrt{(2r)^{2}-r^{2}}=\sqrt{3}\,r\)A1
(c)
cone: \(\dfrac{1}{3}\pi r^{2}\left(\sqrt{3}\,r\right)=\dfrac{\sqrt{3}}{3}\pi r^{3}\)M1FT from (b).
hemisphere: \(\dfrac{2}{3}\pi r^{3}\)M1
\(\dfrac{\frac{\sqrt{3}}{3}\pi r^{3}}{\frac{2}{3}\pi r^{3}}\)A1Must see the ratio formed before simplifying.
\(=\dfrac{\sqrt{3}}{2}\)AG
(d)
\(\cos\theta=\dfrac{r}{2r}=\dfrac{1}{2}\) or \(\tan\theta=\sqrt{3}\)(M1)
\(\dfrac{\pi}{3}\)A1Award A0 for \(60^{\circ}\).

Answers: (b) \(\sqrt{3}\,r\) · (d) \(\dfrac{\pi}{3}\)

20AASL3-q00153.2 Right-angled and non-right-angled trigonometry Paper 1Medium7 marks

In triangle \(ABC\), \(AB=5\) cm, \(BC=7\) cm and \(AC=8\) cm.

(a)

Show that \(\cos B\hat{A}C=\dfrac{1}{2}\).

(2)
(b)

Hence find the exact area of triangle \(ABC\).

(3)
(c)

Find the exact shortest distance from \(B\) to the line \((AC)\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos B\hat{A}C=\dfrac{5^{2}+8^{2}-7^{2}}{2(5)(8)}\)M1Or \(7^{2}=5^{2}+8^{2}-2(5)(8)\cos B\hat{A}C\).
\(=\dfrac{40}{80}\)A1
\(\cos B\hat{A}C=\dfrac{1}{2}\)AG
(b)
\(\sin B\hat{A}C=\dfrac{\sqrt{3}}{2}\)(A1)Or \(B\hat{A}C=\dfrac{\pi}{3}\) (or \(60^{\circ}\)).
\(\dfrac{1}{2}(5)(8)\left(\dfrac{\sqrt{3}}{2}\right)\)M1
\(10\sqrt{3}\text{ cm}^{2}\)A1
(c)
\(\dfrac{1}{2}(8)h=10\sqrt{3}\) or \(h=5\sin\dfrac{\pi}{3}\)(M1)FT from (b).
\(\dfrac{5\sqrt{3}}{2}\) cmA1

Answers: (b) \(10\sqrt{3}\text{ cm}^{2}\) · (c) \(\dfrac{5\sqrt{3}}{2}\) cm

21AASL3-q00163.2 Right-angled and non-right-angled trigonometry Paper 1Medium9 marks

In triangle \(ABC\), \(BC=6\) cm, \(AC=4\) cm and \(\cos A\hat{C}B=-\dfrac{1}{3}\).

(a)

Find the exact length of \([AB]\).

(3)
(b)

Find the exact value of \(\sin A\hat{C}B\).

(2)
(c)

Find the exact area of triangle \(ABC\).

(2)
(d)

Find the exact value of \(\sin B\hat{A}C\). Give your answer in the form \(\dfrac{p\sqrt{q}}{17}\), where \(p,q\in\mathbb{Z}^{+}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(AB^{2}=6^{2}+4^{2}-2(6)(4)\left(-\dfrac{1}{3}\right)\)M1
\(AB^{2}=52+16=68\)A1
\(AB=2\sqrt{17}\) cmA1Accept \(\sqrt{68}\).
(b)
\(\sin^{2}A\hat{C}B=1-\dfrac{1}{9}\)(M1)Or a right-angled triangle with adjacent 1 and hypotenuse 3.
\(\dfrac{2\sqrt{2}}{3}\)A1Award A0 for \(\pm\dfrac{2\sqrt{2}}{3}\).
(c)
\(\dfrac{1}{2}(6)(4)\left(\dfrac{2\sqrt{2}}{3}\right)\)(M1)FT from (b).
\(8\sqrt{2}\text{ cm}^{2}\)A1
(d)
\(\dfrac{\sin B\hat{A}C}{6}=\dfrac{\frac{2\sqrt{2}}{3}}{2\sqrt{17}}\)(M1)Or \(\dfrac{1}{2}\left(2\sqrt{17}\right)(4)\sin B\hat{A}C=8\sqrt{2}\). FT from (a), (b) or (c).
\(\dfrac{2\sqrt{34}}{17}\)A1From \(\dfrac{2\sqrt{2}}{\sqrt{17}}\), rationalized.

Answers: (a) \(2\sqrt{17}\) cm · (b) \(\dfrac{2\sqrt{2}}{3}\) · (c) \(8\sqrt{2}\text{ cm}^{2}\) · (d) \(\dfrac{2\sqrt{34}}{17}\)

22AASL3-q00173.2 Right-angled and non-right-angled trigonometry Paper 1Medium7 marks

The lengths of the sides of a triangle are \(x\) cm, \((x+1)\) cm and \((x+2)\) cm, where \(x\gt0\). The largest angle of the triangle is \(120^{\circ}\).

(a)

Show that \(2x^{2}-x-3=0\).

(3)
(b)

Find the value of \(x\).

(2)
(c)

Find the exact area of the triangle.

(2)
Show mark scheme
WorkingMarkNotes
(a)
the largest angle is opposite the longest side: \((x+2)^{2}=x^{2}+(x+1)^{2}-2x(x+1)\cos120^{\circ}\)M1
\(\cos120^{\circ}=-\dfrac{1}{2}\), so \((x+2)^{2}=x^{2}+(x+1)^{2}+x(x+1)\)A1
\(x^{2}+4x+4=3x^{2}+3x+1\)A1Correctly expanded both sides.
\(2x^{2}-x-3=0\)AG
(b)
\((2x-3)(x+1)=0\)(M1)Or the quadratic formula.
\(x=\dfrac{3}{2}\)A1Award A0 if \(x=-1\) is not rejected.
(c)
\(\dfrac{1}{2}\left(\dfrac{3}{2}\right)\left(\dfrac{5}{2}\right)\sin120^{\circ}\)(M1)FT from (b); must use the two sides enclosing the 120° angle.
\(\dfrac{15\sqrt{3}}{16}\text{ cm}^{2}\)A1

Answers: (b) \(x=\dfrac{3}{2}\) · (c) \(\dfrac{15\sqrt{3}}{16}\text{ cm}^{2}\)

23AASL3-q00243.3 Applications of trigonometry Paper 1Medium6 marks

A surveyor stands at point \(P\) on horizontal ground and measures the angle of elevation of the top of a vertical tower as \(45^{\circ}\). She then walks \(18\) m directly towards the base of the tower to point \(Q\), where the angle of elevation of the top of the tower is \(60^{\circ}\). The height of the tower is \(h\) m.

(a)

Show that \(h=27+9\sqrt{3}\).

(4)
(b)

Find the exact distance from \(Q\) to the base of the tower.

(2)
Show mark scheme
WorkingMarkNotes
(a)
distance from \(P\) to the base \(=\dfrac{h}{\tan45^{\circ}}=h\)M1
distance from \(Q\) to the base \(=\dfrac{h}{\tan60^{\circ}}=\dfrac{h}{\sqrt{3}}\)M1
\(h-\dfrac{h}{\sqrt{3}}=18\Rightarrow h=\dfrac{18\sqrt{3}}{\sqrt{3}-1}\)A1
\(h=\dfrac{18\sqrt{3}\left(\sqrt{3}+1\right)}{(\sqrt{3}-1)(\sqrt{3}+1)}=\dfrac{54+18\sqrt{3}}{2}\)A1Must see rationalization of the denominator.
\(h=27+9\sqrt{3}\)AG
(b)
\(\dfrac{27+9\sqrt{3}}{\sqrt{3}}\) or \(h-18\)(M1)
\(9+9\sqrt{3}\) mA1

Answers: (b) \(9+9\sqrt{3}\) m

24AASL3-q00363.4 Radian measure, arcs and sectors Paper 1Medium7 marks
π/3OABr cm

The diagram shows a sector \(OAB\) of a circle with centre \(O\) and radius \(r\) cm, where \(A\hat{O}B=\dfrac{\pi}{3}\). The shaded region is the segment bounded by the chord \([AB]\) and the arc \(AB\).

(a)

Show that the area of the shaded region is \(\dfrac{r^{2}}{12}\left(2\pi-3\sqrt{3}\right)\text{ cm}^{2}\).

(3)
(b)

The area of the shaded region is \(\left(6\pi-9\sqrt{3}\right)\text{ cm}^{2}\). Find the value of \(r\).

(2)
(c)

Hence find the exact perimeter of the shaded region.

(2)
Show mark scheme
WorkingMarkNotes
(a)
area of sector \(=\dfrac{1}{2}r^{2}\left(\dfrac{\pi}{3}\right)=\dfrac{\pi r^{2}}{6}\)M1
area of triangle \(=\dfrac{1}{2}r^{2}\sin\dfrac{\pi}{3}=\dfrac{\sqrt{3}}{4}r^{2}\)M1
\(\dfrac{\pi r^{2}}{6}-\dfrac{\sqrt{3}r^{2}}{4}=\dfrac{2\pi r^{2}-3\sqrt{3}r^{2}}{12}\)A1Must see the subtraction with a common denominator.
\(\dfrac{r^{2}}{12}\left(2\pi-3\sqrt{3}\right)\)AG
(b)
\(\dfrac{r^{2}}{12}\left(2\pi-3\sqrt{3}\right)=3\left(2\pi-3\sqrt{3}\right)\Rightarrow r^{2}=36\)M1
\(r=6\)A1Award A0 if \(r=-6\) is also given as a final answer.
(c)
arc \(=6\times\dfrac{\pi}{3}=2\pi\) and chord \(AB=6\) (triangle \(OAB\) is equilateral)(M1)FT from (b).
\(\left(2\pi+6\right)\) cmA1

Answers: (b) \(r=6\) · (c) \(2\pi+6\) cm

25AASL3-q00383.4 Radian measure, arcs and sectors Paper 1Medium6 marks

A sector of a circle has radius \(15\) cm and angle \(\theta\) radians. The two straight edges of the sector are joined, without overlap, to form the curved surface of a right circular cone with base radius \(9\) cm.

(a)

Find the exact value of \(\theta\).

(2)
(b)

Find the height of the cone.

(2)
(c)

Find the exact volume of the cone.

(2)
Show mark scheme
WorkingMarkNotes
(a)
arc length of the sector = circumference of the base: \(15\theta=2\pi(9)\)(M1)
\(\theta=\dfrac{6\pi}{5}\)A1
(b)
slant height \(=15\): \(h=\sqrt{15^{2}-9^{2}}\)(M1)Recognizing the radius of the sector becomes the slant height.
\(12\) cmA1
(c)
\(\dfrac{1}{3}\pi(9)^{2}(12)\)(M1)FT from (b).
\(324\pi\text{ cm}^{3}\)A1

Answers: (a) \(\dfrac{6\pi}{5}\) · (b) \(12\) cm · (c) \(324\pi\text{ cm}^{3}\)

26AASL3-q00393.4 Radian measure, arcs and sectors Paper 1Medium9 marks
OTABr2r
Diagram not to scale

The diagram shows a circle with centre \(O\) and radius \(r\) cm. The point \(T\) is such that \(OT=2r\) cm. The lines \((TA)\) and \((TB)\) are tangents to the circle at \(A\) and \(B\). The shaded region is bounded by \([TA]\), \([TB]\) and the minor arc \(AB\).

(a)

Show that \(A\hat{O}T=\dfrac{\pi}{3}\).

(2)
(b)

Show that the area of the shaded region is \(\left(\sqrt{3}-\dfrac{\pi}{3}\right)r^{2}\text{ cm}^{2}\).

(3)
(c)

Find an expression, in terms of \(r\), for the exact perimeter of the shaded region.

(2)
(d)

For one value of \(r\), the area of the shaded region in cm2 is numerically equal to its perimeter in cm. Show that this value is \(r=\dfrac{2\left(3\sqrt{3}+\pi\right)}{3\sqrt{3}-\pi}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(O\hat{A}T=\dfrac{\pi}{2}\) (tangent perpendicular to radius), so \(\cos A\hat{O}T=\dfrac{r}{2r}\)M1
\(\cos A\hat{O}T=\dfrac{1}{2}\)A1
\(A\hat{O}T=\dfrac{\pi}{3}\)AG
(b)
area of kite \(OATB=2\times\dfrac{1}{2}(r)\left(\sqrt{3}\,r\right)=\sqrt{3}\,r^{2}\)M1\(AT=\sqrt{4r^{2}-r^{2}}=\sqrt{3}\,r\).
area of sector \(OAB=\dfrac{1}{2}r^{2}\left(\dfrac{2\pi}{3}\right)=\dfrac{\pi r^{2}}{3}\)M1
\(\sqrt{3}\,r^{2}-\dfrac{\pi r^{2}}{3}\)A1Must see the subtraction.
\(\left(\sqrt{3}-\dfrac{\pi}{3}\right)r^{2}\)AG
(c)
\(TA=TB=\sqrt{3}\,r\) and arc \(AB=r\left(\dfrac{2\pi}{3}\right)\)(M1)Award for either correct length.
\(\left(2\sqrt{3}+\dfrac{2\pi}{3}\right)r\) cmA1Accept equivalent forms, e.g. \(\dfrac{2r\left(3\sqrt{3}+\pi\right)}{3}\).
(d)
\(\left(\sqrt{3}-\dfrac{\pi}{3}\right)r^{2}=\left(2\sqrt{3}+\dfrac{2\pi}{3}\right)r\) and dividing by \(r\;(r\neq0)\)M1FT from (c).
\(r=\dfrac{2\sqrt{3}+\frac{2\pi}{3}}{\sqrt{3}-\frac{\pi}{3}}=\dfrac{6\sqrt{3}+2\pi}{3\sqrt{3}-\pi}\)A1Must see numerator and denominator multiplied by 3, or equivalent.
\(r=\dfrac{2\left(3\sqrt{3}+\pi\right)}{3\sqrt{3}-\pi}\)AG

Answers: (c) \(\left(2\sqrt{3}+\dfrac{2\pi}{3}\right)r\) cm

27AASL3-q00453.5 The unit circle and the ambiguous case Paper 1Medium7 marks
θP(−5/13, 12/13)xyO1−1

The point \(P\left(-\dfrac{5}{13},\,\dfrac{12}{13}\right)\) lies on the unit circle with centre \(O\). The angle between the positive \(x\)-axis and \([OP]\), measured anticlockwise, is \(\theta\).

(a)

Write down the value of \(\tan\theta\).

(1)
(b)

Find the value of \(\sin2\theta\).

(2)
(c)

Find the value of \(\cos2\theta\).

(2)
(d)

The point \(Q\) on the unit circle is such that the angle between the positive \(x\)-axis and \([OQ]\), measured anticlockwise, is \(\theta+\pi\). Write down the coordinates of \(Q\).

(1)
(e)

Write down the equation of the line \((PQ)\).

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan\theta=-\dfrac{12}{5}\)A1
(b)
\(2\left(\dfrac{12}{13}\right)\left(-\dfrac{5}{13}\right)\)(M1)Must use \(\sin\theta=\frac{12}{13}\), \(\cos\theta=-\frac{5}{13}\).
\(-\dfrac{120}{169}\)A1
(c)
\(\left(-\dfrac{5}{13}\right)^{2}-\left(\dfrac{12}{13}\right)^{2}\)(M1)Or \(1-2\left(\frac{12}{13}\right)^{2}\) or \(2\left(\frac{5}{13}\right)^{2}-1\).
\(-\dfrac{119}{169}\)A1
(d)
\(Q\left(\dfrac{5}{13},\,-\dfrac{12}{13}\right)\)A1
(e)
\(y=-\dfrac{12}{5}x\)A1Accept \(y=x\tan\theta\) with their value; FT from (a).

Answers: (a) \(-\dfrac{12}{5}\) · (b) \(-\dfrac{120}{169}\) · (c) \(-\dfrac{119}{169}\) · (d) \(\left(\dfrac{5}{13},-\dfrac{12}{13}\right)\) · (e) \(y=-\dfrac{12}{5}x\)

28AASL3-q00483.5 The unit circle and the ambiguous case Paper 1Medium6 marks

The line \(L\) passes through the origin \(O\) and makes an angle of \(\dfrac{2\pi}{3}\) with the positive \(x\)-axis, measured anticlockwise.

(a)

Find the equation of \(L\), giving your answer in the form \(y=mx\), where \(m\) is exact.

(2)
(b)

The line \(L\) meets the unit circle \(x^{2}+y^{2}=1\) at the points \(A\) and \(B\), where \(A\) lies in the second quadrant. Find the exact coordinates of \(A\) and of \(B\).

(2)
(c)

The line \(M\) has equation \(y=x\). Find the acute angle between \(L\) and \(M\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(y=x\tan\dfrac{2\pi}{3}\)(M1)
\(y=-\sqrt3\,x\)A1
(b)
\(A\left(\cos\frac{2\pi}{3},\,\sin\frac{2\pi}{3}\right)=\left(-\dfrac12,\,\dfrac{\sqrt3}{2}\right)\)A1
\(B\left(\dfrac12,\,-\dfrac{\sqrt3}{2}\right)\)A1FT: \(B\) is the reflection of their \(A\) in \(O\).
(c)
\(M\) makes an angle of \(\dfrac{\pi}{4}\) with the positive \(x\)-axis; \(\dfrac{2\pi}{3}-\dfrac{\pi}{4}\)(M1)
\(\dfrac{5\pi}{12}\)A1Accept \(75^{\circ}\).

Answers: (a) \(y=-\sqrt3x\) · (b) \(A\left(-\frac12,\frac{\sqrt3}{2}\right)\), \(B\left(\frac12,-\frac{\sqrt3}{2}\right)\) · (c) \(\frac{5\pi}{12}\)

29AASL3-q00493.5 The unit circle and the ambiguous case Paper 1Medium6 marks

It is given that \(\cos\dfrac{\pi}{5}=\dfrac{1+\sqrt5}{4}\).

(a)

Find the exact value of \(\cos\dfrac{2\pi}{5}\).

(2)
(b)(i)

Hence write down the exact value of

\(\cos\dfrac{3\pi}{5}\);

(1)
(b)(ii)

\(\cos\dfrac{8\pi}{5}\).

(1)
(c)

Find the exact value of \(\sin^{2}\dfrac{\pi}{5}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(2\left(\dfrac{1+\sqrt5}{4}\right)^{2}-1=\dfrac{6+2\sqrt5}{8}-1\)(M1)
\(\dfrac{\sqrt5-1}{4}\)A1Accept \(\dfrac{2\sqrt5-2}{8}\).
(b)(i)
\(\dfrac{1-\sqrt5}{4}\)A1\(\cos\left(\pi-\frac{2\pi}{5}\right)=-\cos\frac{2\pi}{5}\). FT their (a).
(b)(ii)
\(\dfrac{\sqrt5-1}{4}\)A1\(\cos\left(2\pi-\frac{2\pi}{5}\right)=\cos\frac{2\pi}{5}\). FT their (a).
(c)
\(1-\left(\dfrac{1+\sqrt5}{4}\right)^{2}=1-\dfrac{6+2\sqrt5}{16}\)(M1)Or \(\sin^{2}\frac{\pi}{5}=\frac{1-\cos\frac{2\pi}{5}}{2}\).
\(\dfrac{5-\sqrt5}{8}\)A1Accept \(\dfrac{10-2\sqrt5}{16}\).

Answers: (a) \(\frac{\sqrt5-1}{4}\) · (b) \(\frac{1-\sqrt5}{4}\), \(\frac{\sqrt5-1}{4}\) · (c) \(\frac{5-\sqrt5}{8}\)

30AASL3-q00503.5 The unit circle and the ambiguous case Paper 1Medium9 marks

The point \(P(\cos\theta,\,\sin\theta)\) lies on the unit circle with centre \(O\), where \(0\lt\theta\lt\dfrac{\pi}{2}\). The point \(Q\) is the reflection of \(P\) in the \(y\)-axis and the point \(R\) is the reflection of \(P\) in \(O\).

xyθPQRO1−1
Diagram not to scale
(a)

Write down the coordinates of \(Q\) and of \(R\) in terms of \(\theta\).

(2)
(b)

Show that the area of triangle \(PQR\) is \(2\sin\theta\cos\theta\).

(2)
(c)

The points \(Q\) and \(R\) can also be written as \(Q(\cos\alpha,\,\sin\alpha)\) and \(R(\cos\beta,\,\sin\beta)\), where \(0\lt\alpha\lt2\pi\) and \(0\lt\beta\lt2\pi\). Write down \(\alpha\) and \(\beta\) in terms of \(\theta\).

(2)
(d)

Given that the gradient of the line \((RP)\) is \(\dfrac12\), find the exact area of triangle \(PQR\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(Q(-\cos\theta,\,\sin\theta)\)A1
\(R(-\cos\theta,\,-\sin\theta)\)A1
(b)
\(PQ=2\cos\theta\) and \(QR=2\sin\theta\), with a right angle at \(Q\)M1
area \(=\dfrac12(2\cos\theta)(2\sin\theta)\)A1
\(=2\sin\theta\cos\theta\)AG
(c)
\(\alpha=\pi-\theta\)A1
\(\beta=\pi+\theta\)A1
(d)
\((RP)\) passes through \(O\), so \(\tan\theta=\dfrac12\)(M1)line through the origin: \(y=x\tan\theta\)
\(\sin\theta=\dfrac{1}{\sqrt5}\) and \(\cos\theta=\dfrac{2}{\sqrt5}\)(M1)e.g. from a right-angled triangle with sides 1, 2, \(\sqrt5\) (\(\theta\) acute).
area \(=2\left(\dfrac{1}{\sqrt5}\right)\left(\dfrac{2}{\sqrt5}\right)=\dfrac45\)A1Or \(\dfrac12(2\cos\theta)(2\sin\theta)\) with their values.

Answers: (a) \(Q(-\cos\theta,\sin\theta)\), \(R(-\cos\theta,-\sin\theta)\) · (c) \(\alpha=\pi-\theta\), \(\beta=\pi+\theta\) · (d) \(\frac45\)

31AASL3-q00573.6 Trigonometric identities Paper 1Medium7 marks
(a)

Show that \(\cos^{4}x-\sin^{4}x=\cos2x\).

(2)
(b)

Hence find the exact value of \(\cos^{4}\dfrac{\pi}{8}-\sin^{4}\dfrac{\pi}{8}\).

(2)
(c)

Hence solve the equation \(\cos^{4}x-\sin^{4}x=\dfrac{1}{2}\) for \(0\le x\le\pi\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\left(\cos^{2}x-\sin^{2}x\right)\left(\cos^{2}x+\sin^{2}x\right)\)M1Difference of two squares.
\(\left(\cos^{2}x-\sin^{2}x\right)(1)\) and \(\cos^{2}x-\sin^{2}x=\cos2x\)A1Both identities must be seen.
\(\cos^{4}x-\sin^{4}x=\cos2x\)AG
(b)
\(\cos\left(2\times\dfrac{\pi}{8}\right)=\cos\dfrac{\pi}{4}\)(M1)
\(\dfrac{\sqrt{2}}{2}\)A1Accept \(\dfrac{1}{\sqrt{2}}\).
(c)
\(\cos2x=\dfrac{1}{2}\)(M1)
\(2x=\dfrac{\pi}{3},\ \dfrac{5\pi}{3}\)(A1)Must consider \(0\le2x\le2\pi\).
\(x=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)A1Award A0 if extra values in \([0,\pi]\) are given.

Answers: (b) \(\dfrac{\sqrt{2}}{2}\) · (c) \(x=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)

32AASL3-q00603.6 Trigonometric identities Paper 1Medium9 marks

The diagram shows triangle \(ABC\) with \(AB=AC=6\) cm and \(B\hat{A}C=2\theta\), where \(\cos\theta=\dfrac{2}{3}\) and \(0\lt\theta\lt\dfrac{\pi}{2}\).

2θABC6 cm6 cm
Diagram not to scale
(a)

Show that \(\sin2\theta=\dfrac{4\sqrt5}{9}\).

(3)
(b)

Hence find the exact area of triangle \(ABC\).

(2)
(c)

Find the exact value of \(\cos2\theta\).

(2)
(d)

Hence, or otherwise, find the exact length of \([BC]\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\sin^{2}\theta=1-\dfrac49\)(M1)
\(\sin\theta=\dfrac{\sqrt5}{3}\)A1Positive since \(\theta\) is acute.
\(\sin2\theta=2\left(\dfrac{\sqrt5}{3}\right)\left(\dfrac23\right)\)A1
\(=\dfrac{4\sqrt5}{9}\)AG
(b)
\(\dfrac12(6)(6)\sin2\theta=18\times\dfrac{4\sqrt5}{9}\)(M1)
\(8\sqrt5\text{ cm}^{2}\)A1
(c)
\(\cos2\theta=2\left(\dfrac23\right)^{2}-1\)(M1)Or any correct double angle identity.
\(-\dfrac19\)A1
(d)
\(BC^{2}=36+36-72\left(-\dfrac19\right)=80\)(M1)Or \(BC=2\times6\sin\theta\).
\(4\sqrt5\) cmA1Accept \(\sqrt{80}\).

Answers: (b) \(8\sqrt5\text{ cm}^{2}\) · (c) \(-\frac19\) · (d) \(4\sqrt5\) cm

33AASL3-q00613.6 Trigonometric identities Paper 1Medium11 marks

In triangle \(ABC\), \(AB=9\) cm, \(AC=6\) cm, \(A\hat{B}C=\theta\) and \(A\hat{C}B=2\theta\).

(a)

Show that \(\cos\theta=\dfrac34\).

(3)
(b)

Find the exact value of \(\sin2\theta\).

(3)
(c)

Find the exact value of \(\cos2\theta\).

(1)
(d)

By drawing the perpendicular from \(A\) to \([BC]\), or otherwise, find \(BC\).

(2)
(e)

Find the exact area of triangle \(ABC\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{9}{\sin2\theta}=\dfrac{6}{\sin\theta}\)M1
\(9\sin\theta=6(2\sin\theta\cos\theta)\)M1
dividing by \(\sin\theta\ne0\): \(12\cos\theta=9\)A1Must state or imply \(\sin\theta\ne0\).
\(\cos\theta=\dfrac34\)AG
(b)
\(\sin^{2}\theta=1-\dfrac{9}{16}\)(M1)
\(\sin\theta=\dfrac{\sqrt7}{4}\)A1
\(\sin2\theta=2\left(\dfrac{\sqrt7}{4}\right)\left(\dfrac34\right)=\dfrac{3\sqrt7}{8}\)A1
(c)
\(\cos2\theta=2\left(\dfrac34\right)^{2}-1=\dfrac18\)A1
(d)
\(BC=9\cos\theta+6\cos2\theta=\dfrac{27}{4}+\dfrac34\)(M1)Both angles at \(B\) and \(C\) are acute, so the foot of the perpendicular lies on \([BC]\).
\(BC=7.5\) cmA1Accept \(\dfrac{15}{2}\).
(e)
\(\dfrac12(7.5)(9)\sin\theta\) or \(\dfrac12(7.5)(6)\sin2\theta\)(M1)FT their BC.
\(\dfrac{135\sqrt7}{16}\text{ cm}^{2}\)A1Accept \(\dfrac{67.5\sqrt7}{8}\).

Answers: (b) \(\frac{3\sqrt7}{8}\) · (c) \(\frac18\) · (d) 7.5 cm · (e) \(\frac{135\sqrt7}{16}\text{ cm}^{2}\)

34AASL3-q00623.6 Trigonometric identities Paper 1Medium7 marks

It is given that \(\cos2x=\dfrac{7}{25}\), where \(0\lt x\lt\dfrac{\pi}{2}\).

(a)

Find the exact value of \(\cos x\).

(3)
(b)

Find the exact value of \(\sin2x\).

(2)
(c)

Hence find the exact value of \(\sin4x\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(2\cos^{2}x-1=\dfrac{7}{25}\)M1
\(\cos^{2}x=\dfrac{16}{25}\)A1
\(\cos x=\dfrac45\)A1Award A0 for \(\pm\frac45\) (\(x\) is acute).
(b)
\(\sin x=\dfrac35\) and \(\sin2x=2\left(\dfrac35\right)\left(\dfrac45\right)\)(M1)Or \(\sin2x=\sqrt{1-\left(\frac{7}{25}\right)^{2}}\), positive since \(0\lt2x\lt\pi\).
\(\dfrac{24}{25}\)A1
(c)
\(\sin4x=2\sin2x\cos2x=2\left(\dfrac{24}{25}\right)\left(\dfrac{7}{25}\right)\)(M1)
\(\dfrac{336}{625}\)A1

Answers: (a) \(\frac45\) · (b) \(\frac{24}{25}\) · (c) \(\frac{336}{625}\)

35AASL3-q00663.7 Circular functions and their graphs Paper 1Medium7 marks
(π/6, 5)(2π/3, −1)xyOπ

Let \(f(x)=a\sin\big(b(x+c)\big)+d\), where \(a,b\gt0\) and \(0\lt c\lt\dfrac{\pi}{2}\). The diagram shows the graph of \(y=f(x)\) for \(0\le x\le\pi\). The graph has a maximum point at \(\left(\dfrac{\pi}{6},\,5\right)\) and a minimum point at \(\left(\dfrac{2\pi}{3},\,-1\right)\).

(a)

Write down the value of \(a\) and the value of \(d\).

(2)
(b)

Find the value of \(b\).

(2)
(c)

Find the value of \(c\).

(2)
(d)

Write down the number of solutions of the equation \(f(x)=4\) for \(0\le x\le\pi\).

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(a=3\)A1
\(d=2\)A1
(b)
period \(=2\left(\dfrac{2\pi}{3}-\dfrac{\pi}{6}\right)=\pi\)(M1)
\(b=\dfrac{2\pi}{\pi}=2\)A1
(c)
\(2\left(\dfrac{\pi}{6}+c\right)=\dfrac{\pi}{2}\)(M1)Or substituting \(\left(\frac{\pi}{6},5\right)\): \(3\sin\big(2(\frac{\pi}{6}+c)\big)+2=5\). FT from (a), (b).
\(c=\dfrac{\pi}{12}\)A1
(d)
\(2\)A1

Answers: (a) \(a=3,\ d=2\) · (b) \(b=2\) · (c) \(c=\dfrac{\pi}{12}\) · (d) \(2\)

36AASL3-q00683.7 Circular functions and their graphs Paper 1Medium8 marks

Let \(g(x)=2\cos\left(3\left(x-\dfrac{\pi}{4}\right)\right)+1\), for \(x\in\mathbb{R}\).

(a)

Describe a sequence of transformations that maps the graph of \(y=\cos x\) onto the graph of \(y=g(x)\).

(4)
(b)

Write down the range of \(g\).

(2)
(c)

Find the least positive value of \(x\) at which \(g\) has a maximum.

(2)
Show mark scheme
WorkingMarkNotes
(a)
horizontal stretch (parallel to the \(x\)-axis) with scale factor \(\dfrac{1}{3}\)A1Award marks for any four correct transformations in a valid order.
then translation by \(\dfrac{\pi}{4}\) in the positive \(x\)-directionA1If the translation is done before the horizontal stretch, it must be by \(\dfrac{3\pi}{4}\).
vertical stretch (parallel to the \(y\)-axis) with scale factor \(2\)A1
then translation by \(1\) in the positive \(y\)-directionA1If the vertical translation is done before the vertical stretch, it must be by \(\dfrac{1}{2}\).
(b)
lower bound \(-1\)A1Award A1 for each correct end point; for full marks accept \(-1\le y\le3\) or \([-1,3]\).
upper bound \(3\)A1
(c)
\(3\left(x-\dfrac{\pi}{4}\right)=0\) (or \(2k\pi\))(M1)
\(x=\dfrac{\pi}{4}\)A1

Answers: (b) \(-1\le g(x)\le3\) · (c) \(x=\dfrac{\pi}{4}\)

37AASL3-q00703.7 Circular functions and their graphs Paper 1Medium9 marks

Let \(f(x)=2\cos2x+1\), for \(0\le x\le\pi\).

(a)

Find the \(x\)-intercepts of the graph of \(f\).

(3)
(b)

Sketch the graph of \(y=f(x)\), showing the coordinates of the end points and of the minimum point.

(3)
(c)

Hence find the set of values of \(x\) for which \(f(x)\gt2\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos2x=-\dfrac12\), with \(0\le2x\le2\pi\)M1
\(2x=\dfrac{2\pi}{3},\ \dfrac{4\pi}{3}\)(A1)
\(x=\dfrac{\pi}{3},\ \dfrac{2\pi}{3}\)A1
(b)
end points \((0,\,3)\) and \((\pi,\,3)\)A1
minimum point \(\left(\dfrac{\pi}{2},\,-1\right)\)A1
correct shape: smooth curve symmetric about \(x=\dfrac{\pi}{2}\), crossing the \(x\)-axis at their interceptsA1
(c)
\(\cos2x=\dfrac12\)M1
\(x=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)A1
\(0\le x\lt\dfrac{\pi}{6}\) or \(\dfrac{5\pi}{6}\lt x\le\pi\)A1Accept strict or non-strict inequality at 0 and π; endpoints π/6 and 5π/6 must be excluded.

Answers: (a) \(\frac{\pi}{3},\frac{2\pi}{3}\) · (c) \(0\le x\lt\frac{\pi}{6}\) or \(\frac{5\pi}{6}\lt x\le\pi\)

38AASL3-q00713.7 Circular functions and their graphs Paper 1Medium10 marks

The graph of \(y=\sin x\) is transformed onto the graph of \(y=g(x)\) by the following sequence of transformations:

  • a vertical stretch with scale factor \(3\);
  • a horizontal stretch with scale factor \(\dfrac12\);
  • a translation by the vector \(\begin{pmatrix}\frac{\pi}{6}\\-1\end{pmatrix}\).
(a)

Find \(g(x)\), giving your answer in the form \(g(x)=a\sin\big(b(x+c)\big)+d\).

(3)
(b)

The point \(\left(\dfrac{\pi}{2},\,1\right)\) on the graph of \(y=\sin x\) is mapped to the point \(M\) on the graph of \(y=g(x)\). Find the coordinates of \(M\).

(2)
(c)

Find the exact value of \(g(0)\).

(2)
(d)

Solve the equation \(g(x)=\dfrac12\), for \(0\le x\le\pi\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(a=3\)A1
\(b=2\)A1
\(c=-\dfrac{\pi}{6}\) and \(d=-1\), so \(g(x)=3\sin\left(2\left(x-\dfrac{\pi}{6}\right)\right)-1\)A1Award A0 for \(3\sin\left(2x-\frac{\pi}{6}\right)-1\).
(b)
\(x\)-coordinate \(\dfrac12\times\dfrac{\pi}{2}+\dfrac{\pi}{6}=\dfrac{5\pi}{12}\)A1
\(y\)-coordinate \(3(1)-1=2\), so \(M\left(\dfrac{5\pi}{12},\,2\right)\)A1
(c)
\(3\sin\left(-\dfrac{\pi}{3}\right)-1\)(M1)
\(-\dfrac{3\sqrt3}{2}-1\)A1Accept \(-\dfrac{3\sqrt3+2}{2}\).
(d)
\(\sin\left(2x-\dfrac{\pi}{3}\right)=\dfrac12\), with \(-\dfrac{\pi}{3}\le2x-\dfrac{\pi}{3}\le\dfrac{5\pi}{3}\)M1
\(2x-\dfrac{\pi}{3}=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)(A1)
\(x=\dfrac{\pi}{4},\ \dfrac{7\pi}{12}\)A1Award A0 if additional values are given.

Answers: (a) \(g(x)=3\sin\left(2\left(x-\frac{\pi}{6}\right)\right)-1\) · (b) \(M\left(\frac{5\pi}{12},2\right)\) · (c) \(-\frac{3\sqrt3}{2}-1\) · (d) \(\frac{\pi}{4},\frac{7\pi}{12}\)

39AASL3-q00813.8 Trigonometric equations Paper 1Medium6 marks

Consider the equation \(2\cos^{2}x+3\sin x-3=0\), for \(0\le x\le2\pi\).

(a)

Show that the equation can be written as \(2\sin^{2}x-3\sin x+1=0\).

(2)
(b)

Hence solve the equation \(2\cos^{2}x+3\sin x-3=0\), for \(0\le x\le2\pi\).

(4)
Show mark scheme
WorkingMarkNotes
(a)
\(2\left(1-\sin^{2}x\right)+3\sin x-3=0\)M1
\(-2\sin^{2}x+3\sin x-1=0\)A1
\(2\sin^{2}x-3\sin x+1=0\)AG
(b)
\(\left(2\sin x-1\right)\left(\sin x-1\right)=0\)M1Or quadratic formula.
\(\sin x=\dfrac{1}{2}\) or \(\sin x=1\)A1
\(x=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)A1
\(x=\dfrac{\pi}{2}\)A1Award A0 if extra values in the interval are given.

Answers: (b) \(x=\dfrac{\pi}{6},\ \dfrac{\pi}{2},\ \dfrac{5\pi}{6}\)

40AASL3-q00833.8 Trigonometric equations Paper 1Medium7 marks

Consider the equation \(\cos2x+3\cos x+2=0\), for \(-\pi\le x\le\pi\).

(a)

Show that the equation can be written as \(2\cos^{2}x+3\cos x+1=0\).

(2)
(b)

Hence solve the equation \(\cos2x+3\cos x+2=0\), for \(-\pi\le x\le\pi\).

(5)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos2x=2\cos^{2}x-1\)M1
\(2\cos^{2}x-1+3\cos x+2\)A1
\(2\cos^{2}x+3\cos x+1=0\)AG
(b)
\((2\cos x+1)(\cos x+1)=0\)M1Or quadratic formula.
\(\cos x=-\dfrac12\) or \(\cos x=-1\)A1
\(x=\pm\dfrac{2\pi}{3}\)A1
\(x=\pi\)A1
\(x=-\pi\)A1Award the final A1 only if exactly four solutions are given.

Answers: (b) \(x=-\pi,\,-\frac{2\pi}{3},\,\frac{2\pi}{3},\,\pi\)

41AASL3-q00463.5 The unit circle and the ambiguous case Paper 1Hard8 marks

In triangle \(ABC\), \(AB=10\) cm, \(BC=6\) cm and \(B\hat{A}C=30^{\circ}\).

(a)

Show that \(\sin A\hat{C}B=\dfrac{5}{6}\).

(2)
(b)

Explain why there are two possible triangles \(ABC\) that satisfy this information.

(2)
(c)

By using the cosine rule, find the two possible exact values of \(AC\).

(4)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{\sin A\hat{C}B}{10}=\dfrac{\sin30^{\circ}}{6}\)M1
\(\sin A\hat{C}B=\dfrac{10\times\frac{1}{2}}{6}\)A1
\(\sin A\hat{C}B=\dfrac{5}{6}\)AG
(b)
\(A\hat{C}B\) may be acute (\(C_{1}\)) or obtuse, \(C_{2}=180^{\circ}-C_{1}\), since both have sine \(\dfrac{5}{6}\)R1
since \(\dfrac{5}{6}\gt\dfrac{1}{2}=\sin30^{\circ}\), \(C_{1}\gt30^{\circ}\), so \(C_{2}+30^{\circ}\lt180^{\circ}\) and the obtuse case gives a valid triangleR1Accept equivalent: \(AB\sin30^{\circ}=5\lt BC=6\lt AB=10\).
(c)
\(6^{2}=10^{2}+x^{2}-2(10)x\cos30^{\circ}\), where \(x=AC\)M1
\(x^{2}-10\sqrt{3}\,x+64=0\)A1
\(x=\dfrac{10\sqrt{3}\pm\sqrt{300-256}}{2}\)M1Correct substitution into the quadratic formula, or completing the square.
\(AC=5\sqrt{3}+\sqrt{11}\) or \(AC=5\sqrt{3}-\sqrt{11}\)A1Both values required.

Answers: (c) \(AC=5\sqrt{3}\pm\sqrt{11}\) cm

42AASL3-q00543.5 The unit circle and the ambiguous case Paper 1Hard13 marks

In triangle \(ABC\), \(AB=12\) cm, \(B\hat{A}C=30^{\circ}\), \(BC=x\) cm and \(AC=y\) cm.

(a)

Show that \(y^{2}-12\sqrt3\,y+144-x^{2}=0\).

(2)
(b)

By considering this equation as a quadratic in \(y\), find the set of values of \(x\) for which two different triangles \(ABC\) can be drawn.

(4)
(c)

For a particular value of \(x\), two different triangles can be drawn and the length of \([AC]\) in one triangle is twice the length of \([AC]\) in the other. Find this value of \(x\).

(4)
(d)

For the value of \(x\) found in part (c), find the two possible sizes of \(A\hat{C}B\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(x^{2}=12^{2}+y^{2}-2(12)(y)\cos30^{\circ}\)M1
\(\cos30^{\circ}=\dfrac{\sqrt3}{2}\), so \(x^{2}=144+y^{2}-12\sqrt3\,y\)A1
\(y^{2}-12\sqrt3\,y+144-x^{2}=0\)AG
(b)
two distinct roots: \(\left(12\sqrt3\right)^{2}-4\left(144-x^{2}\right)\gt0\)M1
\(4x^{2}\gt144\), so \(x\gt6\)A1since \(x\gt0\)
both roots must be positive: their sum is \(12\sqrt3\gt0\), so their product \(144-x^{2}\gt0\)R1
\(6\lt x\lt12\)A1
(c)
roots \(k\) and \(2k\): \(3k=12\sqrt3\)M1
\(k=4\sqrt3\)A1so \(AC=4\sqrt3\) or \(8\sqrt3\)
product of roots \(2k^{2}=144-x^{2}\), i.e. \(96=144-x^{2}\)M1Or substitute \(y=4\sqrt3\) into the equation in (a).
\(x=4\sqrt3\)A1Accept \(\sqrt{48}\). Award A0 if \(-4\sqrt3\) is also given.
(d)
valid method for one triangle, e.g. \(AC=BC=4\sqrt3\), so the triangle is isosceles with \(A\hat{B}C=30^{\circ}\); or \(AB^{2}+BC^{2}=144+48=192=AC^{2}\)(M1)Or sine rule: \(\sin A\hat{C}B=\dfrac{12\sin30^{\circ}}{4\sqrt3}=\dfrac{\sqrt3}{2}\).
\(120^{\circ}\) (when \(AC=4\sqrt3\))A1
\(60^{\circ}\) (when \(AC=8\sqrt3\))A1

Answers: (b) \(6\lt x\lt 12\) · (c) \(x=4\sqrt3\) · (d) \(120^{\circ}\) and \(60^{\circ}\)

43AASL3-q00583.6 Trigonometric identities Paper 1Hard7 marks

The angle \(x\) satisfies \(\sin x+\cos x=\dfrac{1}{2}\), where \(\dfrac{\pi}{2}\lt x\lt\pi\).

(a)

Show that \(\sin2x=-\dfrac{3}{4}\).

(2)
(b)

Find the exact value of \(\cos2x\).

(4)
(c)

Hence find the exact value of \(\tan2x\).

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(\left(\sin x+\cos x\right)^{2}=\sin^{2}x+2\sin x\cos x+\cos^{2}x=\dfrac{1}{4}\)M1
\(1+\sin2x=\dfrac{1}{4}\)A1
\(\sin2x=-\dfrac{3}{4}\)AG
(b)
\(\left(\cos x-\sin x\right)^{2}=1-\sin2x=\dfrac{7}{4}\)M1Or \(\cos^{2}2x=1-\dfrac{9}{16}=\dfrac{7}{16}\).
\(\cos x\lt0\) and \(\sin x\gt0\) for \(\dfrac{\pi}{2}\lt x\lt\pi\), so \(\cos x-\sin x\lt0\)R1Alternative R1: \(\sin x+\cos x\gt0\) with \(\cos x\lt0\) gives \(\dfrac{\pi}{2}\lt x\lt\dfrac{3\pi}{4}\), so \(\pi\lt2x\lt\dfrac{3\pi}{2}\) and \(\cos2x\lt0\).
\(\cos x-\sin x=-\dfrac{\sqrt{7}}{2}\)A1In the alternative method, award for \(\cos2x=\pm\dfrac{\sqrt{7}}{4}\).
\(\cos2x=\left(\cos x-\sin x\right)\left(\cos x+\sin x\right)=-\dfrac{\sqrt{7}}{4}\)A1Award A0 for \(\pm\dfrac{\sqrt{7}}{4}\) with no choice made.
(c)
\(\tan2x=\dfrac{-\frac{3}{4}}{-\frac{\sqrt{7}}{4}}=\dfrac{3}{\sqrt{7}}=\dfrac{3\sqrt{7}}{7}\)A1FT from (b).

Answers: (b) \(-\dfrac{\sqrt{7}}{4}\) · (c) \(\dfrac{3\sqrt{7}}{7}\)

44AASL3-q00633.6 Trigonometric identities Paper 1Hard8 marks

Let \(g(x)=8\sin^{2}x\cos^{2}x\), for \(x\in\mathbb{R}\).

(a)

Show that \(g(x)=1-\cos4x\).

(3)
(b)

Write down the period of \(g\) and the range of \(g\).

(2)
(c)

Solve the equation \(g(x)=1\), for \(0\le x\le\pi\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(8\sin^{2}x\cos^{2}x=2(2\sin x\cos x)^{2}\)M1
\(=2\sin^{2}2x\)A1
using \(\cos4x=1-2\sin^{2}2x\), so \(2\sin^{2}2x=1-\cos4x\)M1
\(g(x)=1-\cos4x\)AG
(b)
period \(\dfrac{\pi}{2}\)A1
\(0\le g(x)\le2\)A1Accept \([0,\,2]\).
(c)
\(\cos4x=0\), with \(0\le4x\le4\pi\)M1
\(4x=\dfrac{\pi}{2},\dfrac{3\pi}{2},\dfrac{5\pi}{2},\dfrac{7\pi}{2}\)(A1)
\(x=\dfrac{\pi}{8},\ \dfrac{3\pi}{8},\ \dfrac{5\pi}{8},\ \dfrac{7\pi}{8}\)A1All four and no others.

Answers: (b) period \(\frac{\pi}{2}\), range \(0\le g(x)\le2\) · (c) \(\frac{\pi}{8},\frac{3\pi}{8},\frac{5\pi}{8},\frac{7\pi}{8}\)

45AASL3-q00733.7 Circular functions and their graphs Paper 1Hard10 marks

Let \(f(x)=2\sin\left(x-\dfrac{\pi}{3}\right)+1\), for \(0\le x\le2\pi\).

(a)

Find the exact value of \(f(0)\).

(2)
(b)

Find the coordinates of the maximum point and of the minimum point of the graph of \(f\).

(3)
(c)

Solve the equation \(f(x)=0\).

(3)
(d)

For \(1-\sqrt3\lt k\lt3\), the equation \(f(x)=k\) has exactly two solutions, \(\alpha\) and \(\beta\). Find the value of \(\alpha+\beta\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(2\sin\left(-\dfrac{\pi}{3}\right)+1\)(M1)
\(1-\sqrt3\)A1
(b)
\(x-\dfrac{\pi}{3}=\dfrac{\pi}{2}\) or \(\dfrac{3\pi}{2}\)(M1)
maximum \(\left(\dfrac{5\pi}{6},\,3\right)\)A1
minimum \(\left(\dfrac{11\pi}{6},\,-1\right)\)A1
(c)
\(\sin\left(x-\dfrac{\pi}{3}\right)=-\dfrac12\), with \(-\dfrac{\pi}{3}\le x-\dfrac{\pi}{3}\le\dfrac{5\pi}{3}\)M1
\(x-\dfrac{\pi}{3}=-\dfrac{\pi}{6},\ \dfrac{7\pi}{6}\)(A1)Award (A1) only if \(\frac{11\pi}{6}\) is not used.
\(x=\dfrac{\pi}{6},\ \dfrac{3\pi}{2}\)A1
(d)
the graph is symmetric about the line through the maximum, \(x=\dfrac{5\pi}{6}\), so \(\dfrac{\alpha+\beta}{2}=\dfrac{5\pi}{6}\)R1
\(\alpha+\beta=\dfrac{5\pi}{3}\)A1

Answers: (a) \(1-\sqrt3\) · (b) \(\left(\frac{5\pi}{6},3\right)\), \(\left(\frac{11\pi}{6},-1\right)\) · (c) \(\frac{\pi}{6},\frac{3\pi}{2}\) · (d) \(\frac{5\pi}{3}\)

46AASL3-q00843.8 Trigonometric equations Paper 1Hard9 marks

Consider the equation \(\sin2x=\sin x\), for \(-\pi\le x\le3\pi\).

(a)

Show that the equation can be written as \(\sin x(2\cos x-1)=0\).

(2)
(b)

Hence solve the equation \(\sin2x=\sin x\), for \(-\pi\le x\le3\pi\).

(5)
(c)

Hence find the number of solutions of the equation \(\sin4x=\sin2x\), for \(-\dfrac{\pi}{2}\le x\le\dfrac{3\pi}{2}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(2\sin x\cos x=\sin x\)M1
\(2\sin x\cos x-\sin x=0\)A1Award A0 if the equation is divided by \(\sin x\).
\(\sin x(2\cos x-1)=0\)AG
(b)
\(\sin x=0\) or \(\cos x=\dfrac12\)M1
\(x=-\pi,\ 0,\ \pi\)A1
\(x=2\pi,\ 3\pi\)A1
\(x=-\dfrac{\pi}{3},\ \dfrac{\pi}{3}\)A1
\(x=\dfrac{5\pi}{3},\ \dfrac{7\pi}{3}\)A1Nine solutions in total.
(c)
letting \(u=2x\): \(\sin2u=\sin u\) with \(-\pi\le u\le3\pi\)M1
\(9\)A1FT their number of solutions in (b).

Answers: (b) \(-\pi,-\frac{\pi}{3},0,\frac{\pi}{3},\pi,\frac{5\pi}{3},2\pi,\frac{7\pi}{3},3\pi\) · (c) 9

47AASL3-q00903.8 Trigonometric equations Paper 1Hard16 marks

Let \(f(x)=4\sin x\cos x+1\), for \(0\le x\le\pi\).

(a)

Show that \(f(x)=2\sin2x+1\).

(1)
(b)

Write down the amplitude and the period of \(f\).

(2)
(c)

Find the coordinates of the maximum point and of the minimum point of the graph of \(f\).

(3)
(d)

Solve the equation \(f(x)=0\).

(4)
(e)

Sketch the graph of \(y=f(x)\), showing the coordinates of the end points, the maximum and minimum points and the \(x\)-intercepts.

(3)
(f)

Find the values of \(k\) for which the equation \(f(x)=k\) has exactly two solutions.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(4\sin x\cos x=2\left(2\sin x\cos x\right)=2\sin2x\)M1
\(f(x)=2\sin2x+1\)AG
(b)
amplitude \(2\)A1
period \(\pi\)A1
(c)
\(\sin2x=1\) or \(\sin2x=-1\)(M1)
maximum \(\left(\dfrac{\pi}{4},\,3\right)\)A1
minimum \(\left(\dfrac{3\pi}{4},\,-1\right)\)A1
(d)
\(\sin2x=-\dfrac{1}{2}\)M1
\(2x=\dfrac{7\pi}{6},\ \dfrac{11\pi}{6}\)(A1)Must consider \(0\le2x\le2\pi\).
\(x=\dfrac{7\pi}{12}\)A1
\(x=\dfrac{11\pi}{12}\)A1Award A0 for any extra values.
(e)
sine-shaped curve over one period, starting at \((0,1)\) and ending at \((\pi,1)\)A1
maximum at \(\left(\frac{\pi}{4},3\right)\) and minimum at \(\left(\frac{3\pi}{4},-1\right)\) labelledA1FT from (c).
\(x\)-intercepts \(\frac{7\pi}{12}\) and \(\frac{11\pi}{12}\) labelledA1FT from (d).
(f)
considering horizontal lines \(y=k\) on the sketch; \(k=1\) meets the graph three times (at \(0\), \(\frac{\pi}{2}\), \(\pi\))(M1)
\(-1\lt k\lt1\)A1
\(1\lt k\lt3\)A1Award A0 if \(k=1\) is included. Accept \(-1\lt k\lt3,\ k\neq1\) for both A1 marks.

Answers: (b) amplitude \(2\), period \(\pi\) · (c) max \(\left(\dfrac{\pi}{4},3\right)\), min \(\left(\dfrac{3\pi}{4},-1\right)\) · (d) \(\dfrac{7\pi}{12},\ \dfrac{11\pi}{12}\) · (f) \(-1\lt k\lt1\) or \(1\lt k\lt3\)

48AASL3-q00913.8 Trigonometric equations Paper 1Hard14 marks

Let \(f(x)=\cos2x+\sin x\), for \(0\le x\le2\pi\).

(a)

Show that \(f(x)=1+\sin x-2\sin^{2}x\).

(1)
(b)

Solve the equation \(f(x)=0\).

(5)
(c)

By writing \(s=\sin x\), or otherwise, find the maximum value of \(f\).

(3)
(d)

Find the minimum value of \(f\).

(2)
(e)

Find the number of solutions of the equation \(f(x)=1\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\cos2x=1-2\sin^{2}x\), so \(f(x)=1-2\sin^{2}x+\sin x\)A1
\(f(x)=1+\sin x-2\sin^{2}x\)AG
(b)
\(2\sin^{2}x-\sin x-1=0\)M1
\((2\sin x+1)(\sin x-1)=0\)A1
\(\sin x=1\) or \(\sin x=-\dfrac12\)A1
\(x=\dfrac{\pi}{2}\)A1
\(x=\dfrac{7\pi}{6},\ \dfrac{11\pi}{6}\)A1
(c)
\(f=-2s^{2}+s+1\), a quadratic in \(s\) with \(-1\le s\le1\)M1
vertex at \(s=\dfrac14\) (which is attainable)(A1)e.g. \(-2\left(s-\frac14\right)^{2}+\frac98\)
maximum value \(\dfrac98\)A1
(d)
minimum at an end of \(-1\le s\le1\): \(s=-1\) gives \(-2\), \(s=1\) gives \(0\)(M1)
\(-2\)A1
(e)
\(\sin x-2\sin^{2}x=0\Rightarrow\sin x(1-2\sin x)=0\)M1
\(\sin x=0\): \(x=0,\ \pi,\ 2\pi\) and \(\sin x=\dfrac12\): \(x=\dfrac{\pi}{6},\ \dfrac{5\pi}{6}\)A1
\(5\)A1

Answers: (b) \(\frac{\pi}{2},\frac{7\pi}{6},\frac{11\pi}{6}\) · (c) \(\frac98\) · (d) \(-2\) · (e) 5

49AASL3-q00103.1 Three-dimensional geometry Paper 2Easy9 marks

A fuel storage tank is in the shape of a right circular cylinder with a hemisphere attached at each end. The cylinder has radius \(3.8\) m and length \(13.8\) m, and each hemisphere has radius \(3.8\) m.

(a)

Find the volume of the tank.

(3)
(b)

Find the external surface area of the tank.

(3)
(c)

The outside of the tank is to be painted with one coat of paint. One litre of paint covers \(12\text{ m}^{2}\) and the paint is sold in \(5\)-litre tins. Find the least number of tins needed.

(3)
Show mark scheme
WorkingMarkNotes
(a)
cylinder: \(\pi(3.8)^{2}(13.8)\;(=626.03)\)(M1)
two hemispheres form a sphere: \(\dfrac{4}{3}\pi(3.8)^{3}\;(=229.85)\)(M1)
\(856\text{ m}^{3}\)A1\(855.878\ldots\)
(b)
curved surface of cylinder \(2\pi(3.8)(13.8)\)(M1)
surface of a sphere \(4\pi(3.8)^{2}\)(M1)No circular end faces included.
\(511\text{ m}^{2}\)A1\(510.948\ldots\)
(c)
\(\dfrac{510.948\ldots}{12}\)(M1)FT from (b).
\(42.6\) litres(A1)\(42.579\ldots\)
\(9\) tinsA1\(42.6\div5=8.52\). Award A0 for 8 or 8.52.

Answers: (a) \(856\text{ m}^{3}\) · (b) \(511\text{ m}^{2}\) · (c) 9 tins

50AASL3-q00193.2 Right-angled and non-right-angled trigonometry Paper 2Easy5 marks
52°71°PQR14 cm

In triangle \(PQR\), \(PQ=14\) cm, \(Q\hat{P}R=52^{\circ}\) and \(P\hat{Q}R=71^{\circ}\).

(a)

Find \(QR\).

(3)
(b)

Find the area of triangle \(PQR\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(P\hat{R}Q=180^{\circ}-52^{\circ}-71^{\circ}=57^{\circ}\)(A1)
\(\dfrac{QR}{\sin52^{\circ}}=\dfrac{14}{\sin57^{\circ}}\)(M1)
\(QR=13.2\) cmA1\(13.1543\ldots\)
(b)
\(\dfrac{1}{2}(14)(13.154\ldots)\sin71^{\circ}\)(M1)FT from (a).
\(87.1\text{ cm}^{2}\)A1\(87.0636\ldots\) Accept \(87.4\) from using \(13.2\).

Answers: (a) \(13.2\) cm · (b) \(87.1\text{ cm}^{2}\)

51AASL3-q00203.2 Right-angled and non-right-angled trigonometry Paper 2Easy7 marks

Building regulations state that a wheelchair ramp must rise no more than \(1\) m vertically for every \(12\) m horizontally. A straight ramp is to be built from the ground to a doorway \(0.75\) m above the ground.

(a)

Write down the least horizontal distance the ramp must cover.

(1)
(b)

Find the greatest angle that the ramp may make with the horizontal.

(2)
(c)

Find the length of the sloping surface of the ramp in part (a).

(2)
(d)

A builder proposes a straight ramp whose sloping surface is \(8.5\) m long, from the ground to the doorway. Determine whether this ramp meets the regulations.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(9\) mA1
(b)
\(\tan\theta=\dfrac{1}{12}\)(M1)Or \(\dfrac{0.75}{9}\).
\(4.76^{\circ}\)A1\(4.76364\ldots^{\circ}\); accept \(0.0831\) radians
(c)
\(\sqrt{9^{2}+0.75^{2}}\)(M1)Or \(\dfrac{0.75}{\sin4.76^{\circ}}\).
\(9.03\) mA1\(9.03119\ldots\)
(d)
\(\sin\alpha=\dfrac{0.75}{8.5}\Rightarrow\alpha=5.06^{\circ}\)(M1)\(5.06209\ldots^{\circ}\). Or \(0.0884\) radians. Or horizontal distance \(\sqrt{8.5^{2}-0.75^{2}}=8.47\lt9\).
\(5.06^{\circ}\gt4.76^{\circ}\), so the ramp is too steep and does not meet the regulationsR1Do not award R1 without a correct comparison. Award (M1)R0 for a correct angle with an incorrect conclusion.

Answers: (a) \(9\) m · (b) \(4.76^{\circ}\) · (c) \(9.03\) m · (d) No (\(5.06^{\circ}\gt4.76^{\circ}\))

52AASL3-q00253.3 Applications of trigonometry Paper 2Easy5 marks
32°55°CDBA7 m

A vertical flagpole \([AB]\) of height \(7\) m stands on horizontal ground, with its base at \(B\). From a point \(C\) on the ground the angle of elevation of the top of the flagpole, \(A\), is \(32^{\circ}\). From a point \(D\) on \([CB]\) the angle of elevation of \(A\) is \(55^{\circ}\).

(a)

Find the distance \(BC\).

(2)
(b)

Find the distance \(CD\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan32^{\circ}=\dfrac{7}{BC}\)(M1)
\(BC=11.2\) mA1\(11.2023\ldots\)
(b)
\(\tan55^{\circ}=\dfrac{7}{BD}\)(M1)
\(BD=4.90\) m(A1)\(4.90145\ldots\)
\(CD=11.202\ldots-4.901\ldots=6.30\) mA1\(6.30088\ldots\) Accept \(6.3\). FT from (a).

Answers: (a) \(11.2\) m · (b) \(6.30\) m

53AASL3-q00293.3 Applications of trigonometry Paper 2Easy5 marks

The banks of a river are straight and parallel. Two points \(P\) and \(Q\) are \(30\) m apart on one bank. A tree \(T\) stands on the opposite bank. It is measured that \(T\hat{P}Q=75^{\circ}\) and \(T\hat{Q}P=50^{\circ}\).

(a)

Write down the size of \(P\hat{T}Q\).

(1)
(b)

Find \(QT\).

(2)
(c)

Find the width of the river.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(55^{\circ}\)A1
(b)
\(\dfrac{QT}{\sin75^{\circ}}=\dfrac{30}{\sin55^{\circ}}\)(M1)
\(35.4\) mA1\(35.3753\ldots\)
(c)
width \(=35.37\ldots\times\sin50^{\circ}\)(M1)Perpendicular distance from \(T\) to the line \((PQ)\). FT from (b).
\(27.1\) mA1\(27.0990\ldots\)

Answers: (a) \(55^{\circ}\) · (b) \(35.4\) m · (c) \(27.1\) m

54AASL3-q00413.4 Radian measure, arcs and sectors Paper 2Easy7 marks
O2.212 cm42 cm
Diagram not to scale

A windscreen wiper rotates about the point \(O\) through an angle of \(2.2\) radians. The rubber blade lies along the arm, from \(12\) cm to \(54\) cm from \(O\). The shaded region shows the area of the windscreen wiped by the blade.

(a)

Find the area wiped by the blade.

(2)
(b)

Find the perimeter of the wiped region.

(3)
(c)

The wiper takes \(0.75\) seconds to rotate through the \(2.2\) radians. Find the average speed of the tip of the blade, in cm s−1.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{1}{2}(54)^{2}(2.2)-\dfrac{1}{2}(12)^{2}(2.2)\)(M1)
\(3050\text{ cm}^{2}\)A1\(3049.2\) exactly. Accept \(3049.2\).
(b)
arcs: \(54(2.2)=118.8\) and \(12(2.2)=26.4\)(M1)
adding two straight edges of \(54-12=42\) cm(M1)
\(229\) cmA1\(229.2\) exactly.
(c)
\(\dfrac{118.8}{0.75}\)(M1)FT from their outer arc.
\(158\text{ cm s}^{-1}\)A1\(158.4\) exactly.

Answers: (a) \(3050\text{ cm}^{2}\) · (b) \(229\) cm · (c) \(158\text{ cm s}^{-1}\)

55AASL3-q00533.5 The unit circle and the ambiguous case Paper 2Easy6 marks

In triangle \(PQR\), \(PQ=8\) cm, \(QR=11\) cm and \(Q\hat{P}R=40^{\circ}\).

(a)

Find \(P\hat{R}Q\).

(2)
(b)

Explain why there is only one triangle \(PQR\) that satisfies this information.

(2)
(c)

Find \(PR\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{\sin P\hat{R}Q}{8}=\dfrac{\sin40^{\circ}}{11}\)(M1)\(\sin P\hat{R}Q=0.467481\ldots\)
\(27.9^{\circ}\)A1\(27.8709\ldots^{\circ}\)
(b)
the other angle with this sine is \(180^{\circ}-27.9^{\circ}=152.1^{\circ}\)A1
\(152.1^{\circ}+40^{\circ}\gt 180^{\circ}\), so this angle is impossibleR1Accept: the side opposite the given angle (11 cm) is longer than \(PQ\), so \(P\hat{R}Q\) must be acute.
(c)
\(P\hat{Q}R=180^{\circ}-40^{\circ}-27.87^{\circ}=112.1^{\circ}\) and \(\dfrac{PR}{\sin112.1^{\circ}}=\dfrac{11}{\sin40^{\circ}}\)(M1)
\(15.9\) cmA1\(15.8523\ldots\)

Answers: (a) \(27.9^{\circ}\) · (c) 15.9 cm

56AASL3-q00063.1 Three-dimensional geometry Paper 2Medium8 marks

A solid metal sphere has volume \(500\text{ cm}^{3}\).

(a)

Find the radius of the sphere.

(2)
(b)

Find the surface area of the sphere.

(2)
(c)

The sphere is melted down and all of the metal is recast into a solid right circular cone. The radius of the base of the cone is equal to the radius, \(r\) cm, of the sphere. Show that the height of the cone is \(4r\) cm.

(2)
(d)

Find the curved surface area of the cone.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{4}{3}\pi r^{3}=500\)(M1)
\(r=4.92\) cmA1\(4.92372\ldots\)
(b)
\(4\pi(4.92372\ldots)^{2}\)(M1)FT from their \(r\).
\(305\text{ cm}^{2}\)A1\(304.647\ldots\) Accept \(304\)–\(305\).
(c)
\(\dfrac{1}{3}\pi r^{2}h=\dfrac{4}{3}\pi r^{3}\)M1Equating the two volumes in terms of r. Award M0 for working only with 500 and a numerical r.
\(r^{2}h=4r^{3}\)A1
\(h=4r\)AG
(d)
slant height \(l=\sqrt{r^{2}+(4r)^{2}}=r\sqrt{17}\;(=20.3)\) and \(\pi rl\)(M1)
\(314\text{ cm}^{2}\)A1\(314.023\ldots\) FT from their \(r\).

Answers: (a) \(4.92\) cm · (b) \(305\text{ cm}^{2}\) · (d) \(314\text{ cm}^{2}\)

57AASL3-q00073.1 Three-dimensional geometry Paper 2Medium8 marks
ABCDVM10 cm12 cm
Diagram not to scale

The diagram shows a right pyramid \(VABCD\) with a square base of side \(10\) cm. The point \(M\) is the centre of the base and \(V\) is vertically above \(M\), with \(VM=12\) cm.

(a)

Find the volume of the pyramid.

(2)
(b)

Find the angle between the edge \(VA\) and the base \(ABCD\).

(3)
(c)

Find the total surface area of the pyramid.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{1}{3}(10^{2})(12)\)(M1)
\(400\text{ cm}^{3}\)A1
(b)
\(AM=\dfrac{1}{2}\sqrt{10^{2}+10^{2}}=5\sqrt{2}\;(=7.07)\)(M1)
\(\tan V\hat{A}M=\dfrac{12}{7.07\ldots}\)(M1)Must identify angle \(V\hat{A}M\) (or use any correct right-angled triangle).
\(59.5^{\circ}\)A1\(59.4910\ldots^{\circ}\); \(1.04\) radians
(c)
height of a triangular face \(=\sqrt{12^{2}+5^{2}}=13\)(M1)
\(4\times\dfrac{1}{2}(10)(13)+10^{2}\)(M1)Four triangular faces plus the base.
\(360\text{ cm}^{2}\)A1

Answers: (a) \(400\text{ cm}^{3}\) · (b) \(59.5^{\circ}\) · (c) \(360\text{ cm}^{2}\)

58AASL3-q00093.1 Three-dimensional geometry Paper 2Medium8 marks
r3r2r
Diagram not to scale

A solid is made from a right circular cylinder of radius \(r\) cm and height \(3r\) cm, with a solid right circular cone of base radius \(r\) cm and height \(2r\) cm fixed to its top face, as shown in the diagram.

(a)

Show that the volume of the solid is \(\dfrac{11}{3}\pi r^{3}\text{ cm}^{3}\).

(2)
(b)

The volume of the solid is \(2000\text{ cm}^{3}\). Find the value of \(r\).

(2)
(c)

Show that the slant height of the cone is \(\sqrt{5}\,r\) cm.

(1)
(d)

Find the total surface area of the solid.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\pi r^{2}(3r)+\dfrac{1}{3}\pi r^{2}(2r)\)M1Sum of the volumes of the cylinder and the cone, both in terms of r.
\(3\pi r^{3}+\dfrac{2}{3}\pi r^{3}\)A1
\(\dfrac{11}{3}\pi r^{3}\)AG
(b)
\(\dfrac{11}{3}\pi r^{3}=2000\)(M1)
\(r=5.58\)A1\(5.57874\ldots\)
(c)
\(l=\sqrt{r^{2}+(2r)^{2}}=\sqrt{5r^{2}}\)A1Must see the Pythagoras step.
\(l=\sqrt{5}\,r\)AG
(d)
cylinder: base \(\pi r^{2}\) and curved surface \(2\pi r(3r)=6\pi r^{2}\)(M1)Award M0 if the top face of the cylinder (inside the solid) is included.
cone: curved surface \(\pi r(\sqrt{5}\,r)\); total \(=(7+\sqrt{5})\pi r^{2}\)(M1)
\(903\text{ cm}^{2}\)A1\(903.045\ldots\) FT from (b). Accept \(902\)–\(904\).

Answers: (b) \(r=5.58\) · (d) \(903\text{ cm}^{2}\)

59AASL3-q00113.1 Three-dimensional geometry Paper 2Medium9 marks
NABCDVM16 cm10 cm9 cm
Diagram not to scale

The diagram shows a right pyramid \(VABCD\) with a horizontal rectangular base \(ABCD\), where \(AB=16\) cm and \(BC=10\) cm. The point \(M\) is the point of intersection of the diagonals of the base, and \(V\) is vertically above \(M\) with \(VM=9\) cm.

(a)

Find the length of the edge \([VA]\).

(2)
(b)

The point \(N\) is the midpoint of \([BC]\). Find the angle between the line \([VN]\) and the base \(ABCD\).

(2)
(c)

Find the size of the angle \(A\hat{V}C\).

(2)
(d)

Find the total surface area of the pyramid.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(AM=\dfrac{1}{2}\sqrt{16^{2}+10^{2}}=\sqrt{89}\;(=9.43)\) and \(VA=\sqrt{89+9^{2}}\)(M1)
\(VA=\sqrt{170}=13.0\) cmA1\(13.0384\ldots\)
(b)
\(MN=8\) and \(\tan V\hat{N}M=\dfrac{9}{8}\)(M1)Or \(VN=\sqrt{145}\) and \(\sin V\hat{N}M=\dfrac{9}{\sqrt{145}}\). Must identify angle \(V\hat{N}M\); award M0 for \(MN=5\).
\(48.4^{\circ}\)A1\(48.3664\ldots^{\circ}\); \(0.844\) radians
(c)
\(A\hat{V}C=2\times A\hat{V}M\), where \(\tan A\hat{V}M=\dfrac{\sqrt{89}}{9}\)(M1)Or \(180^{\circ}-2\times V\hat{A}M\) with \(\tan V\hat{A}M=\dfrac{9}{\sqrt{89}}\), or the cosine rule in triangle \(AVC\) with \(AC=2\sqrt{89}\).
\(92.7^{\circ}\)A1\(92.6972\ldots^{\circ}\); \(1.62\) radians
(d)
heights of the triangular faces: \(\sqrt{9^{2}+5^{2}}=\sqrt{106}\) (faces on \(AB\), \(CD\)) and \(\sqrt{9^{2}+8^{2}}=\sqrt{145}\) (faces on \(BC\), \(DA\))(M1)Award for either correct face height.
\(2\times\dfrac{1}{2}(16)\sqrt{106}+2\times\dfrac{1}{2}(10)\sqrt{145}+16\times10\)(M1)
\(445\text{ cm}^{2}\)A1\(445.146\ldots\)

Answers: (a) \(13.0\) cm · (b) \(48.4^{\circ}\) · (c) \(92.7^{\circ}\) · (d) \(445\text{ cm}^{2}\)

60AASL3-q00133.1 Three-dimensional geometry Paper 2Medium9 marks

A vertical pole \([OT]\) of height \(12\) m stands on horizontal ground. A coordinate system is set up with \(O\) at the origin, the \(x\)-axis pointing east, the \(y\)-axis pointing north and the \(z\)-axis vertically upwards; units are metres. The ground is the plane \(z=0\). Two straight ropes join the top of the pole, \(T\), to the points \(A(9,\,-4,\,0)\) and \(B(-3,\,8,\,0)\) on the ground.

(a)

Write down the coordinates of \(T\).

(1)
(b)

Find the length of the rope \([TA]\).

(2)
(c)

Find the angle between the rope \([TA]\) and the ground.

(2)
(d)

Find the coordinates of \(M\), the midpoint of \([AB]\).

(1)
(e)

Find the angle of elevation of \(T\) from \(M\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(T(0,\,0,\,12)\)A1
(b)
\(\sqrt{9^{2}+(-4)^{2}+(-12)^{2}}\)(M1)
\(\sqrt{241}=15.5\) mA1\(15.5241\ldots\)
(c)
\(OA=\sqrt{97}\) and \(\tan T\hat{A}O=\dfrac{12}{\sqrt{97}}\)(M1)Or \(\sin T\hat{A}O=\dfrac{12}{\sqrt{241}}\).
\(50.6^{\circ}\)A1\(50.6229\ldots^{\circ}\); \(0.884\) radians
(d)
\(M(3,\,2,\,0)\)A1
(e)
\(OM=\sqrt{3^{2}+2^{2}}=\sqrt{13}\)(A1)FT from (d).
\(\tan T\hat{M}O=\dfrac{12}{\sqrt{13}}\)(M1)Or \(TM=\sqrt{157}=12.5\) and \(\sin T\hat{M}O=\dfrac{12}{\sqrt{157}}\).
\(73.3^{\circ}\)A1\(73.2764\ldots^{\circ}\); \(1.28\) radians

Answers: (a) \((0,0,12)\) · (b) \(15.5\) m · (c) \(50.6^{\circ}\) · (d) \((3,2,0)\) · (e) \(73.3^{\circ}\)

61AASL3-q00213.2 Right-angled and non-right-angled trigonometry Paper 2Medium10 marks

The parallelogram \(ABCD\) has \(AB=13\) cm, \(AD=8\) cm and \(D\hat{A}B=70^{\circ}\).

(a)

Find the length of the diagonal \([BD]\).

(2)
(b)

Find the length of the diagonal \([AC]\).

(3)
(c)

Find the area of the parallelogram.

(2)
(d)

The diagonals intersect at \(X\). Find the acute angle between the diagonals.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(BD^{2}=13^{2}+8^{2}-2(13)(8)\cos70^{\circ}\)(M1)
\(12.7\) cmA1\(12.7224\ldots\)
(b)
\(A\hat{B}C=110^{\circ}\)(A1)Co-interior angles.
\(AC^{2}=13^{2}+8^{2}-2(13)(8)\cos110^{\circ}\)(M1)
\(17.4\) cmA1\(17.4396\ldots\)
(c)
\(2\times\dfrac{1}{2}(13)(8)\sin70^{\circ}\)(M1)Or \(13\times8\sin70^{\circ}\).
\(97.7\text{ cm}^{2}\)A1\(97.7280\ldots\)
(d)
the diagonals bisect each other: \(AX=8.72\), \(DX=6.36\)(M1)FT from (a) and (b).
\(\cos A\hat{X}D=\dfrac{8.719\ldots^{2}+6.361\ldots^{2}-8^{2}}{2(8.719\ldots)(6.361\ldots)}\)(M1)Or area of triangle \(AXD=\dfrac{97.7}{4}=\dfrac{1}{2}(8.72)(6.36)\sin A\hat{X}D\), selecting the acute value.
\(61.8^{\circ}\)A1\(61.7550\ldots^{\circ}\). Award A0 for \(118^{\circ}\) only.

Answers: (a) \(12.7\) cm · (b) \(17.4\) cm · (c) \(97.7\text{ cm}^{2}\) · (d) \(61.8^{\circ}\)

62AASL3-q00233.2 Right-angled and non-right-angled trigonometry Paper 2Medium7 marks

In triangle \(PQR\), \(PQ=8\) cm, \(PR=10\) cm and the area of the triangle is \(30\text{ cm}^{2}\).

(a)

Show that \(\sin Q\hat{P}R=\dfrac{3}{4}\).

(2)
(b)

Find the two possible values of \(Q\hat{P}R\).

(2)
(c)

Given that \(Q\hat{P}R\) is obtuse, find \(QR\).

(2)
(d)

Hence find the perimeter of triangle \(PQR\).

(1)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{1}{2}(8)(10)\sin Q\hat{P}R=30\)M1
\(40\sin Q\hat{P}R=30\)A1
\(\sin Q\hat{P}R=\dfrac{3}{4}\)AG
(b)
\(48.6^{\circ}\)A1\(48.5903\ldots^{\circ}\); \(0.848\) radians
\(131^{\circ}\)A1\(131.409\ldots^{\circ}\); \(2.29\) radians. FT \(180^{\circ}-\) their acute angle.
(c)
\(QR^{2}=8^{2}+10^{2}-2(8)(10)\cos131.409\ldots^{\circ}\)(M1)FT from (b).
\(16.4\) cmA1\(16.4265\ldots\)
(d)
\(34.4\) cmA1\(34.4265\ldots\) FT \(18+\) their (c).

Answers: (b) \(48.6^{\circ}\) or \(131^{\circ}\) · (c) \(16.4\) cm · (d) \(34.4\) cm

63AASL3-q00263.3 Applications of trigonometry Paper 2Medium6 marks
12°20°ABFT45 m
Diagram not to scale

A vertical cliff \([TF]\) is \(45\) m high, where \(F\) is at sea level. A boat sails in a straight line directly towards \(F\). At point \(A\) the angle of depression of the boat from \(T\) is \(12^{\circ}\). Two minutes later the boat is at point \(B\) and the angle of depression is \(20^{\circ}\).

(a)

Find the distance \(FA\).

(2)
(b)

Find the distance \(AB\).

(2)
(c)

Find the average speed of the boat between \(A\) and \(B\), giving your answer in km h−1.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan12^{\circ}=\dfrac{45}{FA}\)(M1)Angle of elevation of \(T\) from \(A\) is \(12^{\circ}\) (alternate angles).
\(FA=212\) mA1\(211.708\ldots\)
(b)
\(FB=\dfrac{45}{\tan20^{\circ}}\;(=123.636\ldots)\) and subtracting(M1)
\(AB=88.1\) mA1\(88.0719\ldots\) FT from (a).
(c)
\(\dfrac{88.07\ldots}{120}=0.734\text{ m s}^{-1}\) or \(\dfrac{0.08807\ldots}{\tfrac{2}{60}}\)(M1)Correct conversion of both units.
\(2.64\text{ km h}^{-1}\)A1\(2.64215\ldots\) FT from (b).

Answers: (a) \(212\) m · (b) \(88.1\) m · (c) \(2.64\text{ km h}^{-1}\)

64AASL3-q00273.3 Applications of trigonometry Paper 2Medium8 marks

Two points \(A\) and \(B\) lie on horizontal ground, \(120\) m apart. A vertical tower \([FT]\) has its base \(F\) on the line segment \([AB]\). The angle of elevation of the top of the tower, \(T\), is \(28^{\circ}\) from \(A\) and \(41^{\circ}\) from \(B\).

(a)

Write down the size of \(A\hat{T}B\).

(1)
(b)

Find \(AT\).

(2)
(c)

Find the height of the tower.

(2)
(d)

An observer walks from \(A\) directly towards the tower and stops at the midpoint of \([AB]\). Find the angle of elevation of \(T\) from this point.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(111^{\circ}\)A1
(b)
\(\dfrac{AT}{\sin41^{\circ}}=\dfrac{120}{\sin111^{\circ}}\)(M1)FT from (a).
\(84.3\) mA1\(84.3281\ldots\)
(c)
\(FT=84.32\ldots\times\sin28^{\circ}\)(M1)Or \(\dfrac{h}{\tan28^{\circ}}+\dfrac{h}{\tan41^{\circ}}=120\).
\(39.6\) mA1\(39.5896\ldots\)
(d)
\(AF=\dfrac{39.58\ldots}{\tan28^{\circ}}=74.46\ldots\) or \(84.32\ldots\cos28^{\circ}\)(M1)
horizontal distance from the midpoint to \(F\) \(=74.46\ldots-60=14.46\ldots\) and \(\tan\theta=\dfrac{39.58\ldots}{14.46\ldots}\)(M1)
\(69.9^{\circ}\)A1\(69.9388\ldots^{\circ}\) FT from (c).

Answers: (a) \(111^{\circ}\) · (b) \(84.3\) m · (c) \(39.6\) m · (d) \(69.9^{\circ}\)

65AASL3-q00303.3 Applications of trigonometry Paper 2Medium11 marks

A vertical radio mast \([MT]\) of height \(40\) m stands on horizontal ground with its base at \(M\). Point \(A\) is \(30\) m from \(M\) on a bearing of \(030^{\circ}\), and point \(B\) is \(25\) m from \(M\) on a bearing of \(140^{\circ}\).

(a)

Find the angle of elevation of \(T\) from \(A\).

(2)
(b)

Find the distance \(AB\).

(3)
(c)

Find the bearing of \(B\) from \(A\).

(3)
(d)

A technician walks in a straight line from \(A\) to \(B\). Find the greatest angle of elevation of \(T\) from the technician during this walk.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan\theta=\dfrac{40}{30}\)(M1)
\(53.1^{\circ}\)A1\(53.1301\ldots^{\circ}\); \(0.927\) radians
(b)
\(A\hat{M}B=140^{\circ}-30^{\circ}=110^{\circ}\)(A1)
\(AB^{2}=30^{2}+25^{2}-2(30)(25)\cos110^{\circ}\)(M1)
\(45.1\) mA1\(45.1445\ldots\)
(c)
\(\dfrac{\sin M\hat{A}B}{25}=\dfrac{\sin110^{\circ}}{45.14\ldots}\Rightarrow M\hat{A}B=31.4^{\circ}\)(M1)\(31.3577\ldots^{\circ}\) FT from (b).
bearing of \(M\) from \(A\) is \(210^{\circ}\); \(210^{\circ}-31.36^{\circ}\)(M1)
\(179^{\circ}\)A1\(178.642\ldots^{\circ}\) Accept \(178.6^{\circ}\).
(d)
greatest elevation occurs at the point of \([AB]\) closest to \(M\) (foot of the perpendicular from \(M\))R1
\(d=30\sin31.36^{\circ}=15.6\) m, or \(\dfrac{2\times\frac{1}{2}(30)(25)\sin110^{\circ}}{45.14}\)(M1)\(15.6113\ldots\)
\(\arctan\dfrac{40}{15.61\ldots}=68.7^{\circ}\)A1\(68.6800\ldots^{\circ}\); \(1.20\) radians

Answers: (a) \(53.1^{\circ}\) · (b) \(45.1\) m · (c) \(179^{\circ}\) · (d) \(68.7^{\circ}\)

66AASL3-q00403.4 Radian measure, arcs and sectors Paper 2Medium7 marks
θOABr

The diagram shows a sector \(OAB\) of a circle with centre \(O\) and radius \(r\) cm. The angle \(A\hat{O}B\) is \(\theta\) radians. The length of the arc \(AB\) is \(10\) cm and the area of the sector is \(35\text{ cm}^{2}\).

(a)

Find the value of \(r\) and the value of \(\theta\).

(4)
(b)

Find the area of the shaded segment.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(r\theta=10\) and \(\dfrac{1}{2}r^{2}\theta=35\)(M1)
\(\dfrac{1}{2}r(r\theta)=35\Rightarrow5r=35\)(M1)Any valid method of eliminating one variable.
\(r=7\)A1
\(\theta=\dfrac{10}{7}\;(=1.43)\)A1\(1.42857\ldots\)
(b)
area of triangle \(OAB=\dfrac{1}{2}(7)^{2}\sin\dfrac{10}{7}\;(=24.25)\)(M1)GDC must be in radian mode. Award M0 for \(\sin1.43^{\circ}\).
\(35-24.25\ldots\)(M1)
\(10.7\text{ cm}^{2}\)A1\(10.7473\ldots\) FT from (a).

Answers: (a) \(r=7\), \(\theta=\dfrac{10}{7}\approx1.43\) · (b) \(10.7\text{ cm}^{2}\)

67AASL3-q00423.4 Radian measure, arcs and sectors Paper 2Medium8 marks

A pendulum consists of a small bob on a light string of length \(80\) cm, attached to a fixed point \(O\). The bob swings in a vertical plane between two extreme positions \(A\) and \(B\). The angle \(A\hat{O}B\) is \(0.6\) radians, and the string is vertical when the bob is midway between \(A\) and \(B\).

(a)

Find the length of the arc travelled by the bob in moving from \(A\) to \(B\).

(2)
(b)

Write down \(A\hat{O}B\) in degrees.

(1)
(c)

Find the straight-line distance \(AB\).

(2)
(d)

Find the height of \(A\) above the lowest point of the bob’s path.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(s=80\times0.6\)(M1)
\(48\) cmA1
(b)
\(34.4^{\circ}\)A1\(34.3774\ldots^{\circ}\)
(c)
\(AB=2\times80\sin0.3\)(M1)Or \(AB^{2}=80^{2}+80^{2}-2(80)(80)\cos0.6\). GDC in radian mode.
\(47.3\) cmA1\(47.2832\ldots\)
(d)
angle between \([OA]\) and the vertical is \(0.3\) radians(M1)
vertical depth of \(A\) below \(O\) \(=80\cos0.3\;(=76.43)\); height \(=80-80\cos0.3\)(M1)
\(3.57\) cmA1\(3.57308\ldots\)

Answers: (a) \(48\) cm · (b) \(34.4^{\circ}\) · (c) \(47.3\) cm · (d) \(3.57\) cm

68AASL3-q00523.5 The unit circle and the ambiguous case Paper 2Medium8 marks

A straight path starts at point \(A\). A post \(B\) is \(12\) m from \(A\), and \([AB]\) makes an angle of \(38^{\circ}\) with the path. A goat is tied to the post with a rope of length \(8.5\) m. When the rope is taut, the goat can reach the path at exactly two points, \(C_{1}\) and \(C_{2}\), as shown.

path38°ABC₁C₂12 m8.5 m8.5 m
Diagram not to scale
(a)

Find the two possible sizes of the angle \(A\hat{C}B\), where \(C\) is a point on the path with \(BC=8.5\) m.

(3)
(b)

Find the distance \(C_{1}C_{2}\).

(3)
(c)

Find the least length of rope for which the goat can just reach the path.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\dfrac{\sin A\hat{C}B}{12}=\dfrac{\sin38^{\circ}}{8.5}\)(M1)\(\sin A\hat{C}B=0.869169\ldots\)
\(60.4^{\circ}\)A1\(60.3622\ldots^{\circ}\)
\(119.6^{\circ}\)A1\(119.637\ldots^{\circ}\). Accept 120°. FT \(180^{\circ}-\) their acute angle.
(b)
triangle \(BC_{1}C_{2}\) is isosceles with base angles \(60.36\ldots^{\circ}\), or \(AC_{1}=5.25\) and \(AC_{2}=13.7\) (cosine rule or sine rule)(M1)
\(C_{1}C_{2}=2(8.5)\cos60.36\ldots^{\circ}\), or \(13.6595\ldots-5.25275\ldots\)(M1)
\(8.41\) mA1\(8.40675\ldots\)
(c)
perpendicular distance from \(B\) to the path, \(12\sin38^{\circ}\)(M1)
\(7.39\) mA1\(7.38793\ldots\)

Answers: (a) \(60.4^{\circ}\) and \(119.6^{\circ}\) · (b) 8.41 m · (c) 7.39 m

69AASL3-q00653.6 Trigonometric identities Paper 2Medium10 marks

The diagram shows a semicircle with centre \(O\) and radius \(10\) cm. The rectangle \(PQRS\) has \(P\) and \(Q\) on the diameter and \(R\) and \(S\) on the arc, and \(O\) is the midpoint of \([PQ]\). The angle \(Q\hat{O}R=\theta\), where \(0\lt\theta\lt\dfrac{\pi}{2}\).

θOPQRS10
Diagram not to scale
(a)

Show that the area of the rectangle is \(100\sin2\theta\text{ cm}^{2}\).

(3)
(b)

Write down the maximum area of the rectangle and the value of \(\theta\) at which it occurs.

(2)
(c)

Find the values of \(\theta\) for which the area of the rectangle is \(80\text{ cm}^{2}\).

(3)
(d)

Find the maximum perimeter of the rectangle.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(QR=10\sin\theta\) and \(OQ=10\cos\theta\)A1
area \(=2(10\cos\theta)(10\sin\theta)=100(2\sin\theta\cos\theta)\)M1
using \(\sin2\theta=2\sin\theta\cos\theta\)A1
area \(=100\sin2\theta\)AG
(b)
\(100\text{ cm}^{2}\)A1
\(\theta=\dfrac{\pi}{4}\)A1Accept 0.785.
(c)
\(100\sin2\theta=80\), e.g. graph of \(y=100\sin2\theta\) with \(y=80\)(M1)
\(\theta=0.464\)A1\(0.463647\ldots\)
\(\theta=1.11\)A1\(1.10714\ldots\)
(d)
perimeter \(=40\cos\theta+20\sin\theta\), maximum from GDC(M1)maximum at \(\theta=0.464\)
\(44.7\) cmA1\(44.7213\ldots=20\sqrt5\)

Answers: (b) 100 cm² at \(\theta=\frac{\pi}{4}\) · (c) 0.464, 1.11 · (d) 44.7 cm

70AASL3-q00743.7 Circular functions and their graphs Paper 2Medium8 marks

The depth of water, \(d\) metres, at the entrance to a harbour \(t\) hours after midnight is modelled by \(d(t)=2.6\cos\big(q(t-3)\big)+4.2\), for \(0\le t\le24\), where \(q\gt0\). The time between consecutive high tides is \(12.4\) hours.

(a)

Write down the depth of water at high tide.

(1)
(b)

Show that \(q=\dfrac{5\pi}{31}\).

(2)
(c)

Find the time of the first low tide after midnight, giving your answer to the nearest minute in 24-hour clock format.

(2)
(d)

A ship can enter the harbour only when the depth of water is at least \(3\) m. Find the total length of time between midnight and noon during which the ship can enter the harbour.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(6.8\) mA1
(b)
\(\dfrac{2\pi}{q}=12.4\)M1
\(q=\dfrac{2\pi}{12.4}=\dfrac{10\pi}{62}\)A1
\(q=\dfrac{5\pi}{31}\)AG
(c)
\(q(t-3)=\pi\Rightarrow t=3+6.2=9.2\)(M1)Or minimum on GDC graph.
09:12A1Accept 9:12 am.
(d)
solving \(d(t)=3\) on GDC (graph or equation)(M1)
\(t=7.05\) and \(t=11.35\)(A1)\(7.04675\ldots,\ 11.3532\ldots\)
\(7.05+(12-11.35)=7.69\) hoursA1\(7.69350\ldots\) Accept 7 hours 42 minutes.

Answers: (a) \(6.8\) m · (c) 09:12 · (d) \(7.69\) hours

71AASL3-q00753.7 Circular functions and their graphs Paper 2Medium9 marks

The blood pressure, \(P\) mmHg, of a patient at rest is modelled by \(P(t)=98+22\sin(2.5\pi t)\), where \(t\) is the time in seconds, \(t\ge0\). Each period of \(P\) corresponds to one heartbeat.

(a)

Write down the maximum and the minimum blood pressure.

(2)
(b)

Find the number of heartbeats per minute.

(2)
(c)

Find the blood pressure when \(t=1.1\).

(2)
(d)

During exercise, the patient’s maximum and minimum blood pressures are each \(20\,\%\) higher than at rest, and the heart beats \(96\) times per minute. The blood pressure is then modelled by \(Q(t)=p+q\sin(kt)\), where \(p,q,k\gt0\). Find the value of \(p\), the value of \(q\) and the exact value of \(k\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
maximum \(120\) mmHgA1
minimum \(76\) mmHgA1
(b)
period \(=\dfrac{2\pi}{2.5\pi}=0.8\) s(M1)
\(\dfrac{60}{0.8}=75\)A1
(c)
\(98+22\sin(2.75\pi)\)(M1)
\(114\) mmHgA1\(113.556\ldots\)
(d)
new maximum \(144\), new minimum \(91.2\); \(p=\dfrac{144+91.2}{2}=117.6\)A1
\(q=\dfrac{144-91.2}{2}=26.4\)A1FT their (a).
period \(\dfrac{60}{96}=0.625\) s, so \(k=\dfrac{2\pi}{0.625}=3.2\pi\)A1Accept \(\dfrac{16\pi}{5}\). Award A0 for 10.1 only (exact value required).

Answers: (a) 120, 76 · (b) 75 · (c) 114 mmHg · (d) \(p=117.6\), \(q=26.4\), \(k=3.2\pi\)

72AASL3-q00763.7 Circular functions and their graphs Paper 2Medium8 marks

The mean monthly temperature, \(T\) °C, in a city is modelled using sinusoidal regression on a GDC. The calculator gives

\(T(x)=6.2\sin(0.524x-2.09)+14.8\),

where \(x\) is the month number (\(x=1\) for January, \(x=2\) for February, and so on), for \(1\le x\le12\).

(a)

Write \(T(x)\) in the form \(a\sin\big(b(x+c)\big)+d\), giving the value of \(c\) to three significant figures.

(2)
(b)

Find the period of \(T\) and comment on its value in this context.

(2)
(c)

Find the maximum mean monthly temperature predicted by the model, and the month in which it occurs.

(2)
(d)

Find the values of \(x\) for which \(T(x)=18\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(0.524\left(x-\dfrac{2.09}{0.524}\right)\)(M1)
\(T(x)=6.2\sin\big(0.524(x-3.99)\big)+14.8\), so \(c=-3.99\)A1\(-3.98854\ldots\)
(b)
\(\dfrac{2\pi}{0.524}=12.0\)A1\(11.9908\ldots\)
approximately 12 months: the temperatures repeat every yearR1
(c)
\(21.0\) °CA1
JulyA1maximum at \(x=6.99\) \((6.98625\ldots)\)
(d)
graph of \(T\) with \(y=18\), or \(\sin(0.524x-2.09)=\dfrac{3.2}{6.2}\)(M1)
\(x=5.02\) and \(x=8.95\)A1\(5.02352\ldots,\ 8.94898\ldots\)

Answers: (a) \(c=-3.99\) · (b) 12.0 months · (c) 21.0 °C in July · (d) 5.02, 8.95

73AASL3-q00773.7 Circular functions and their graphs Paper 2Medium10 marks

The number of hours of daylight, \(D\), in a town on day \(t\) of the year is modelled by

\(D(t)=3.1\cos\left(\dfrac{2\pi}{365}(t-172)\right)+12.2\), for \(1\le t\le365,\ t\in\mathbb{Z}\),

where \(t=1\) is 1 January.

(a)

Write down the maximum number of hours of daylight and the value of \(t\) at which it occurs.

(2)
(b)

Find the number of hours of daylight on day 50.

(2)
(c)

Find the number of days in the year on which there are more than \(14\) hours of daylight.

(3)
(d)

In a second town, the longest day has \(16.8\) hours of daylight and the shortest day has \(7.6\) hours. These occur on the same days of the year as in the first town, and the second town is modelled by \(E(t)=a\cos\left(\dfrac{2\pi}{365}(t-172)\right)+d\). Find the number of days in the year on which the second town has more hours of daylight than the first town.

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(15.3\) hoursA1
\(t=172\)A1
(b)
\(3.1\cos\left(\dfrac{2\pi}{365}(50-172)\right)+12.2\)(M1)
\(10.6\) hoursA1\(10.6346\ldots\)
(c)
\(D(t)=14\), or graph of \(D\) with \(y=14\)(M1)
\(t=116.7\) and \(t=227.3\)(A1)\(116.738\ldots,\ 227.261\ldots\); so days 117 to 227 inclusive
\(111\) daysA1Award A0 for 110 or 110.5.
(d)
\(a=4.6\) and \(d=12.2\)A1
\(E(t)-D(t)=1.5\cos\left(\dfrac{2\pi}{365}(t-172)\right)\gt0\), or graphs of \(D\) and \(E\) intersecting at \(t=80.75\) and \(t=263.25\)(M1)\(|t-172|\lt91.25\); so days 81 to 263 inclusive
\(183\) daysA1Award A0 for 182 or 182.5.

Answers: (a) 15.3 hours at \(t=172\) · (b) 10.6 hours · (c) 111 days · (d) 183 days

74AASL3-q00863.8 Trigonometric equations Paper 2Medium6 marks

Consider the equation \(5\sin2x=4\cos x\), for \(0^{\circ}\le x\le360^{\circ}\).

(a)

Show that the equation can be written as \(2\cos x\left(5\sin x-2\right)=0\).

(2)
(b)

Hence solve the equation \(5\sin2x=4\cos x\), for \(0^{\circ}\le x\le360^{\circ}\).

(4)
Show mark scheme
WorkingMarkNotes
(a)
\(5\left(2\sin x\cos x\right)=4\cos x\)M1Use of the double angle identity.
\(10\sin x\cos x-4\cos x=0\)A1
\(2\cos x\left(5\sin x-2\right)=0\)AG
(b)
\(\cos x=0\Rightarrow x=90^{\circ},\ 270^{\circ}\)A1Award A0 if the factor \(\cos x\) has been cancelled and these solutions are lost.
\(\sin x=0.4\)(M1)
\(x=23.6^{\circ}\)A1\(23.5781\ldots^{\circ}\)
\(x=156^{\circ}\)A1\(156.421\ldots^{\circ}\) Award A0 for answers given only in radians.

Answers: (b) \(x=23.6^{\circ},\ 90^{\circ},\ 156^{\circ},\ 270^{\circ}\)

75AASL3-q00883.8 Trigonometric equations Paper 2Medium6 marks

Consider the equation \(4\tan\big(3(x-20^{\circ})\big)=2\).

(a)

Solve the equation for \(0^{\circ}\le x\le180^{\circ}\).

(4)
(b)

Find the number of solutions of the equation for \(0^{\circ}\le x\le360^{\circ}\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan\big(3(x-20^{\circ})\big)=0.5\), \(3(x-20^{\circ})=26.565\ldots^{\circ}\)(M1)
\(3(x-20^{\circ})=26.6^{\circ}+180^{\circ}n\), within \(-60^{\circ}\le3(x-20^{\circ})\le480^{\circ}\)(M1)Or a graph of \(y=4\tan(3(x-20))\) with \(y=2\).
\(x=28.9^{\circ}\)A1\(28.8550\ldots^{\circ}\)
\(x=88.9^{\circ},\ 148.9^{\circ}\)A1Award the final A1 only if no extra solutions are given.
(b)
period \(60^{\circ}\), or \(3(x-20^{\circ})\) ranges over \([-60^{\circ},\,1020^{\circ}]\)(M1)
\(6\)A1\(28.9^{\circ},\,88.9^{\circ},\,148.9^{\circ},\,208.9^{\circ},\,268.9^{\circ},\,328.9^{\circ}\)

Answers: (a) \(28.9^{\circ},\,88.9^{\circ},\,148.9^{\circ}\) · (b) 6

76AASL3-q00893.8 Trigonometric equations Paper 2Medium7 marks

Consider the equation \(3\cos2x+1=\dfrac{x}{2}\), where \(x\ge0\).

(a)

Solve the equation for \(0\le x\le2\pi\).

(3)
(b)

Explain why the equation has no solutions for \(x\gt8\).

(2)
(c)

Find the total number of solutions of the equation for \(x\ge0\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
graphs of \(y=3\cos2x+1\) and \(y=\dfrac{x}{2}\), or equivalent(M1)
two correct values from \(0.879,\ 2.39,\ 3.78,\ 5.85\)A1\(0.879338\ldots,\ 2.38860\ldots,\ 3.77668\ldots,\ 5.84564\ldots\)
all four values and no othersA1
(b)
\(3\cos2x+1\le4\) for all \(x\)R1
for \(x\gt8\), \(\dfrac{x}{2}\gt4\), so the two sides cannot be equalR1
(c)
one further solution for \(2\pi\lt x\le8\), at \(x=6.63\)(M1)\(6.62810\ldots\)
\(5\)A1

Answers: (a) 0.879, 2.39, 3.78, 5.85 · (c) 5

77AASL3-q00083.1 Three-dimensional geometry Paper 2Hard9 marks
OABCDEFGM8 cm6 cm4 cm
Diagram not to scale

The diagram shows a cuboid \(OABCDEFG\) in which \(OA=8\) cm, \(OC=6\) cm and \(OD=4\) cm. Coordinates are defined so that \(O\) is the origin and \(A\), \(C\) and \(D\) have coordinates \((8,0,0)\), \((0,6,0)\) and \((0,0,4)\) respectively. The point \(M\) is the midpoint of the edge \([EF]\).

(a)

Write down the coordinates of \(M\).

(1)
(b)

Find the length \(OM\).

(2)
(c)

Find the angle between the line \([OM]\) and the base \(OABC\).

(3)
(d)

Find the size of the angle \(M\hat{O}E\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(M(8,\,3,\,4)\)A1
(b)
\(\sqrt{8^{2}+3^{2}+4^{2}}\)(M1)FT from their \(M\).
\(\sqrt{89}=9.43\) cmA1\(9.43398\ldots\)
(c)
identifying the right-angled triangle \(ONM\), where \(N(8,3,0)\) is vertically below \(M\)(M1)May be seen on the diagram.
\(\sin\theta=\dfrac{4}{\sqrt{89}}\) or \(\tan\theta=\dfrac{4}{\sqrt{73}}\)(M1)
\(25.1^{\circ}\)A1\(25.0873\ldots^{\circ}\); \(0.438\) radians
(d)
\([ME]\) is perpendicular to the face \(OAED\), so triangle \(OEM\) has a right angle at \(E\)(R1)Or finding all three sides \(OE=\sqrt{80}\), \(EM=3\), \(OM=\sqrt{89}\) for the cosine rule.
\(\tan M\hat{O}E=\dfrac{3}{\sqrt{80}}\)(M1)Or \(\cos M\hat{O}E=\dfrac{80+89-9}{2\sqrt{80}\sqrt{89}}\).
\(18.5^{\circ}\)A1\(18.5419\ldots^{\circ}\); \(0.324\) radians

Answers: (a) \((8,3,4)\) · (b) \(9.43\) cm · (c) \(25.1^{\circ}\) · (d) \(18.5^{\circ}\)

78AASL3-q00123.1 Three-dimensional geometry Paper 2Hard9 marks
ABCDEF12 cm5 cm3 cm
Diagram not to scale

The diagram shows a wedge \(ABCDEF\). The base \(ABCD\) is a horizontal rectangle with \(AB=12\) cm and \(BC=5\) cm. The face \(DCFE\) is a vertical rectangle with \(DE=CF=3\) cm. The sloping face \(ABFE\) is a rectangle, and its diagonals \([AF]\) and \([BE]\) are drawn.

(a)

Find the length \(AF\).

(2)
(b)

Find the angle between the line \([AF]\) and the base \(ABCD\).

(2)
(c)

Find the angle between the line \([AE]\) and the base \(ABCD\).

(2)
(d)

Find the acute angle between the diagonals \([AF]\) and \([BE]\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(AF=\sqrt{12^{2}+5^{2}+3^{2}}\)(M1)Or \(AC=13\) then \(\sqrt{13^{2}+3^{2}}\).
\(\sqrt{178}=13.3\) cmA1\(13.3416\ldots\)
(b)
\(F\) is vertically above \(C\): \(\sin F\hat{A}C=\dfrac{3}{\sqrt{178}}\) or \(\tan F\hat{A}C=\dfrac{3}{13}\)(M1)
\(13.0^{\circ}\)A1\(12.9946\ldots^{\circ}\); \(0.227\) radians
(c)
\(E\) is vertically above \(D\): \(\tan E\hat{A}D=\dfrac{3}{5}\)(M1)
\(31.0^{\circ}\)A1\(30.9637\ldots^{\circ}\); \(0.540\) radians
(d)
\(AE=\sqrt{34}\;(=5.83)\); the diagonals of rectangle \(ABFE\) bisect each other at \(X\)(M1)
triangle \(AXE\) is isosceles; \(\tan\left(\tfrac{1}{2}A\hat{X}E\right)=\dfrac{\sqrt{34}/2}{6}\), so \(A\hat{X}E=2\arctan\dfrac{\sqrt{34}}{12}\)(M1)Or the cosine rule in triangle \(AXE\) with \(AX=XE=\dfrac{\sqrt{178}}{2}\).
\(51.8^{\circ}\)A1\(51.8314\ldots^{\circ}\); \(0.905\) radians. Award A0 for \(128^{\circ}\) only.

Answers: (a) \(13.3\) cm · (b) \(13.0^{\circ}\) · (c) \(31.0^{\circ}\) · (d) \(51.8^{\circ}\)

79AASL3-q00143.1 Three-dimensional geometry Paper 2Hard16 marks
V10 cm5 cm12 cm
Diagram not to scale

A bucket has the shape of a frustum of a right circular cone: a cone with its tip removed by a cut parallel to its base. The bottom of the bucket is a horizontal circle of radius \(5\) cm, the open top is a horizontal circle of radius \(10\) cm, and the depth of the bucket is \(12\) cm. When the sloping sides are extended they meet at the point \(V\), vertically below the centre of the bottom.

Ignore the thickness of the material.

(a)

Show that \(V\) is \(12\) cm below the bottom of the bucket.

(2)
(b)

Show that the volume of the bucket is \(700\pi\text{ cm}^{3}\).

(3)
(c)

Write down the capacity of the bucket in litres.

(1)
(d)

The outside of the bucket, including the bottom, is painted. Find the area that is painted.

(4)
(e)

The bucket contains \(1.5\) litres of water. Find the depth of the water.

(4)
(f)

Find the angle between a sloping side of the bucket and the horizontal.

(2)
Show mark scheme
WorkingMarkNotes
(a)
similar triangles: \(\dfrac{h}{5}=\dfrac{h+12}{10}\), where \(h\) is the distance of \(V\) below the bottomM1Any correct ratio statement.
\(10h=5h+60\Rightarrow 5h=60\)A1
\(h=12\) cmAG
(b)
volume = large cone − small coneM1
\(\dfrac{1}{3}\pi(10)^{2}(24)-\dfrac{1}{3}\pi(5)^{2}(12)\)A1
\(800\pi-100\pi\)A1
\(700\pi\text{ cm}^{3}\)AG
(c)
\(2.20\) litresA1\(2.19911\ldots\) Accept \(2.2\).
(d)
slant heights \(\sqrt{10^{2}+24^{2}}=26\) and \(\sqrt{5^{2}+12^{2}}=13\)(M1)
curved surface \(=\pi(10)(26)-\pi(5)(13)\;(=195\pi)\)(M1)
adding the bottom, \(\pi(5)^{2}\)(M1)
\(691\text{ cm}^{2}\)A1\(220\pi=691.150\ldots\)
(e)
water surface at height \(H\) above \(V\) has radius \(\dfrac{5H}{12}\)(M1)Similar triangles.
\(\dfrac{1}{3}\pi\left(\dfrac{5H}{12}\right)^{2}H-100\pi=1500\)(M1)Cone to the water surface minus the small cone, equated to \(1500\text{ cm}^{3}\).
\(H=21.5\)(A1)\(21.5289\ldots\)
depth \(=H-12=9.53\) cmA1\(9.52896\ldots\) Accept \(9.5\).
(f)
\(\tan\theta=\dfrac{12}{5}\) or \(\dfrac{24}{10}\)(M1)Right-angled triangle formed by the axis, a radius and a slant edge.
\(67.4^{\circ}\)A1\(67.3801\ldots^{\circ}\); \(1.18\) radians

Answers: (c) \(2.20\) litres · (d) \(691\text{ cm}^{2}\) · (e) \(9.53\) cm · (f) \(67.4^{\circ}\)

80AASL3-q00223.2 Right-angled and non-right-angled trigonometry Paper 2Hard11 marks

In triangle \(ABC\), the point \(D\) lies on \([AC]\). It is given that \(AB=9\) cm, \(B\hat{A}D=65^{\circ}\), \(A\hat{B}D=52^{\circ}\) and \(DC=5\) cm.

(a)

Find \(BD\).

(3)
(b)

Find \(BC\).

(3)
(c)

Find the area of triangle \(ABC\).

(3)
(d)

Find \(B\hat{C}A\).

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(A\hat{D}B=180^{\circ}-65^{\circ}-52^{\circ}=63^{\circ}\)(A1)
\(\dfrac{BD}{\sin65^{\circ}}=\dfrac{9}{\sin63^{\circ}}\)(M1)
\(9.15\) cmA1\(9.15455\ldots\)
(b)
\(B\hat{D}C=180^{\circ}-63^{\circ}=117^{\circ}\)(A1)
\(BC^{2}=9.154\ldots^{2}+5^{2}-2(9.154\ldots)(5)\cos117^{\circ}\)(M1)FT from (a).
\(12.3\) cmA1\(12.2624\ldots\)
(c)
\(AD=\dfrac{9\sin52^{\circ}}{\sin63^{\circ}}=7.96\)(M1)\(7.95964\ldots\) Or area of \(ABD\) \(=\dfrac{1}{2}(9)(9.15)\sin52^{\circ}=32.5\).
\(\dfrac{1}{2}(9)(7.959\ldots+5)\sin65^{\circ}\)(M1)Or \(32.46+\dfrac{1}{2}(9.15)(5)\sin117^{\circ}\;(=32.46+20.39)\).
\(52.9\text{ cm}^{2}\)A1\(52.8544\ldots\)
(d)
\(\dfrac{\sin B\hat{C}A}{9.154\ldots}=\dfrac{\sin117^{\circ}}{12.26\ldots}\)(M1)Or the cosine rule in triangle \(ABC\) or \(BDC\). FT from (a), (b).
\(41.7^{\circ}\)A1\(41.6965\ldots^{\circ}\). The angle is acute because triangle \(BDC\) already contains the obtuse angle \(117^{\circ}\).

Answers: (a) \(9.15\) cm · (b) \(12.3\) cm · (c) \(52.9\text{ cm}^{2}\) · (d) \(41.7^{\circ}\)

81AASL3-q00283.3 Applications of trigonometry Paper 2Hard10 marks

The top of a lighthouse, \(L\), is \(60\) m vertically above sea level, and the base of the lighthouse is at \(O\). Two boats, \(A\) and \(B\), are on the sea. From \(L\), boat \(A\) is on a bearing of \(220^{\circ}\) with an angle of depression of \(8^{\circ}\), and boat \(B\) is on a bearing of \(295^{\circ}\) with an angle of depression of \(14^{\circ}\).

(a)

Find the horizontal distance \(OA\).

(2)
(b)

Find the horizontal distance \(OB\).

(1)
(c)

Find the distance between the two boats.

(3)
(d)

Find the bearing of \(B\) from \(A\).

(4)
Show mark scheme
WorkingMarkNotes
(a)
\(\tan8^{\circ}=\dfrac{60}{OA}\)(M1)Angle of elevation of L from A equals the angle of depression (alternate angles).
\(427\) mA1\(426.922\ldots\)
(b)
\(OB=\dfrac{60}{\tan14^{\circ}}=241\) mA1\(240.646\ldots\)
(c)
\(A\hat{O}B=295^{\circ}-220^{\circ}=75^{\circ}\)(A1)
\(AB^{2}=426.9\ldots^{2}+240.6\ldots^{2}-2(426.9\ldots)(240.6\ldots)\cos75^{\circ}\)(M1)FT from (a) and (b).
\(432\) mA1\(432.426\ldots\)
(d)
\(\dfrac{\sin O\hat{A}B}{240.6\ldots}=\dfrac{\sin75^{\circ}}{432.4\ldots}\)(M1)Angle at \(A\) is acute since \(OB\lt AB\).
\(O\hat{A}B=32.5^{\circ}\)(A1)\(32.5164\ldots^{\circ}\)
bearing of \(O\) from \(A\) is \(220^{\circ}-180^{\circ}=040^{\circ}\), and \(B\) lies anticlockwise of \([AO]\) as seen from \(A\)(M1)A correct diagram showing the north line at A is sufficient.
\(007.5^{\circ}\)A1\(7.48358\ldots^{\circ}\) Accept \(007^{\circ}\) or \(7.48^{\circ}\).

Answers: (a) \(427\) m · (b) \(241\) m · (c) \(432\) m · (d) \(007.5^{\circ}\)

82AASL3-q00313.3 Applications of trigonometry Paper 2Hard9 marks

A straight hillside slopes upwards at \(18^{\circ}\) to the horizontal. A vertical tree \([BT]\) grows on the hillside with its base at \(B\), where \(B\) is \(25\) m from the point \(P\) at the foot of the slope, measured along the slope. The point \(P\), the base \(B\) and the top of the tree \(T\) lie in the same vertical plane. The angle of elevation of \(T\) from \(P\) is \(48^{\circ}\).

(a)

Draw a clearly labelled diagram to represent this information.

(1)
(b)

Show that \(P\hat{B}T=108^{\circ}\).

(2)
(c)

Find the height of the tree, \(BT\).

(3)
(d)

Find the height of \(T\) above the horizontal through \(P\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
horizontal through \(P\); \([PB]\) at \(18^{\circ}\) labelled \(25\) m; vertical \([BT]\); \([PT]\) at \(48^{\circ}\) to the horizontalA1
(b)
\([BP]\) makes an angle of \(18^{\circ}\) below the horizontal through \(B\), and \([BT]\) makes \(90^{\circ}\) above itM1Or: the slope makes \(90^{\circ}-18^{\circ}=72^{\circ}\) with the vertical on the uphill side, and \(P\hat{B}T=180^{\circ}-72^{\circ}\).
\(P\hat{B}T=90^{\circ}+18^{\circ}\)A1
\(P\hat{B}T=108^{\circ}\)AG
(c)
\(B\hat{P}T=48^{\circ}-18^{\circ}=30^{\circ}\) and \(P\hat{T}B=180^{\circ}-30^{\circ}-108^{\circ}=42^{\circ}\)(A1)
\(\dfrac{BT}{\sin30^{\circ}}=\dfrac{25}{\sin42^{\circ}}\)(M1)
\(18.7\) mA1\(18.6809\ldots\)
(d)
\(PT=\dfrac{25\sin108^{\circ}}{\sin42^{\circ}}=35.5\)(M1)\(35.5332\ldots\) Or height of \(B\) above \(P\) \(=25\sin18^{\circ}=7.73\).
\(35.53\ldots\times\sin48^{\circ}\)(M1)Or \(7.725\ldots+18.68\ldots\).
\(26.4\) mA1\(26.4063\ldots\)

Answers: (c) \(18.7\) m · (d) \(26.4\) m

83AASL3-q00323.3 Applications of trigonometry Paper 2Hard14 marks

A yacht leaves port \(P\) and sails \(18\) km on a bearing of \(050^{\circ}\) to a buoy \(A\). It then sails \(25\) km on a bearing of \(130^{\circ}\) to a lighthouse \(B\).

(a)

Draw a clearly labelled diagram to represent this information.

(2)
(b)

Show that \(P\hat{A}B=100^{\circ}\).

(2)
(c)

Find the distance \(PB\).

(3)
(d)

Find the bearing of \(B\) from \(P\).

(3)
(e)

Write down the bearing of \(P\) from \(B\).

(1)
(f)

Find the shortest distance from \(A\) to the line \((PB)\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
north lines at \(P\) and \(A\); \([PA]\) labelled \(18\) km at \(50^{\circ}\) clockwise from north at \(P\)A1
\([AB]\) labelled \(25\) km at \(130^{\circ}\) clockwise from north at \(A\), and \([PB]\) drawnA1
(b)
bearing of \(P\) from \(A\) is \(050^{\circ}+180^{\circ}=230^{\circ}\)M1Or co-interior angles: angle between north at \(A\) and \([AP]\) is \(130^{\circ}\).
\(230^{\circ}-130^{\circ}\)A1Or \(360^{\circ}-130^{\circ}-130^{\circ}\).
\(P\hat{A}B=100^{\circ}\)AG
(c)
use of the cosine rule(M1)
\(PB^{2}=18^{2}+25^{2}-2(18)(25)\cos100^{\circ}\)(A1)
\(PB=33.2\) kmA1\(33.2458\ldots\)
(d)
\(\dfrac{\sin A\hat{P}B}{25}=\dfrac{\sin100^{\circ}}{33.245\ldots}\)(M1)Or the cosine rule.
\(A\hat{P}B=47.8^{\circ}\)(A1)\(47.778\ldots^{\circ}\)
\(097.8^{\circ}\)A1Accept \(098^{\circ}\). FT \(50^{\circ}+\) their angle.
(e)
\(277.8^{\circ}\)A1Accept \(278^{\circ}\). FT their (d) \(+180^{\circ}\).
(f)
area of triangle \(PAB=\dfrac{1}{2}(18)(25)\sin100^{\circ}\;(=222)\)(M1)Or \(d=18\sin A\hat{P}B\).
\(\dfrac{1}{2}(33.245\ldots)d=221.58\ldots\)(M1)Or \(18\sin47.778\ldots^{\circ}\).
\(13.3\) kmA1\(13.3299\ldots\)

Answers: (c) \(33.2\) km · (d) \(097.8^{\circ}\) · (e) \(277.8^{\circ}\) · (f) \(13.3\) km

84AASL3-q00333.3 Applications of trigonometry Paper 2Hard16 marks
108°40°ABCD85 m60 m95 m
Diagram not to scale

The diagram shows a field \(ABCD\) in the shape of a quadrilateral. \(AB=85\) m, \(BC=60\) m, \(AD=95\) m, \(A\hat{B}C=108^{\circ}\) and \(C\hat{A}D=40^{\circ}\).

(a)

Find \(AC\).

(3)
(b)

Find the area of triangle \(ABC\).

(2)
(c)

Find \(CD\).

(3)
(d)

Find the area of the field.

(3)
(e)

A fence is to be built around the edge of the field. The fencing costs €18.50 per metre. Find the cost of the fence, giving your answer to the nearest euro.

(3)
(f)

A water pipe is to be laid in a straight line from \(C\) to the edge \([AD]\). Find the shortest possible length of the pipe.

(2)
Show mark scheme
WorkingMarkNotes
(a)
use of the cosine rule(M1)
\(AC^{2}=85^{2}+60^{2}-2(85)(60)\cos108^{\circ}\)(A1)
\(118\) mA1\(118.224\ldots\)
(b)
\(\dfrac{1}{2}(85)(60)\sin108^{\circ}\)(M1)
\(2430\text{ m}^{2}\)A1\(2425.19\ldots\)
(c)
use of the cosine rule in triangle \(ACD\)(M1)
\(CD^{2}=118.22\ldots^{2}+95^{2}-2(118.22\ldots)(95)\cos40^{\circ}\)(A1)FT from (a).
\(76.1\) mA1\(76.1223\ldots\)
(d)
area of triangle \(ACD=\dfrac{1}{2}(118.22\ldots)(95)\sin40^{\circ}\)(M1)
\(3610\text{ m}^{2}\)(A1)\(3609.67\ldots\)
\(6030\text{ m}^{2}\)A1\(6034.86\ldots\) FT their (b) \(+\) their area of \(ACD\). Accept \(6035\).
(e)
perimeter \(=85+60+76.12\ldots+95\;(=316.12\ldots)\)(M1)FT from (c). Must not include \(AC\).
\(316.12\ldots\times18.5\)(M1)
€5848A1\(5848.26\ldots\) Award A0 for €5848.26 (not to the nearest euro).
(f)
\(d=AC\sin40^{\circ}=118.22\ldots\times\sin40^{\circ}\)(M1)Or \(\dfrac{2\times\text{area }ACD}{95}\).
\(76.0\) mA1\(75.9930\ldots\) FT from (a).

Answers: (a) \(118\) m · (b) \(2430\text{ m}^{2}\) · (c) \(76.1\) m · (d) \(6030\text{ m}^{2}\) · (e) €5848 · (f) \(76.0\) m

85AASL3-q00343.3 Applications of trigonometry Paper 2Hard15 marks

Two fire-lookout towers, \(A\) and \(B\), stand on level ground, with \(B\) \(12\) km due east of \(A\). A fire is seen at point \(F\). From \(A\) the bearing of \(F\) is \(042^{\circ}\), and from \(B\) the bearing of \(F\) is \(316^{\circ}\).

(a)

Draw a clearly labelled diagram to represent this information.

(2)
(b)

Show that \(A\hat{F}B=86^{\circ}\).

(2)
(c)

Find the distance \(AF\).

(3)
(d)

Find the distance \(BF\).

(2)
(e)

A fire station \(C\) is \(5\) km due south of \(B\). Find the distance from \(C\) to the fire.

(3)
(f)

Find the bearing of \(F\) from \(C\).

(3)
Show mark scheme
WorkingMarkNotes
(a)
\(A\) and \(B\) with \(B\) due east of \(A\), labelled \(12\) km, with north lines at \(A\) and \(B\)A1
\(F\) north of \([AB]\), with the angles \(42^{\circ}\) at \(A\) and \(316^{\circ}\) (or \(44^{\circ}\) west of north) at \(B\) shownA1
(b)
\(F\hat{A}B=90^{\circ}-42^{\circ}=48^{\circ}\) and \(F\hat{B}A=316^{\circ}-270^{\circ}=46^{\circ}\)M1
\(180^{\circ}-48^{\circ}-46^{\circ}\)A1
\(A\hat{F}B=86^{\circ}\)AG
(c)
use of the sine rule(M1)
\(\dfrac{AF}{\sin46^{\circ}}=\dfrac{12}{\sin86^{\circ}}\)(A1)
\(8.65\) kmA1\(8.65315\ldots\)
(d)
\(\dfrac{BF}{\sin48^{\circ}}=\dfrac{12}{\sin86^{\circ}}\)(M1)Or the cosine rule with their AF.
\(8.94\) kmA1\(8.93951\ldots\)
(e)
\(F\hat{B}C=316^{\circ}-180^{\circ}=136^{\circ}\)(A1)
\(CF^{2}=5^{2}+8.939\ldots^{2}-2(5)(8.939\ldots)\cos136^{\circ}\)(M1)FT from (d).
\(13.0\) kmA1\(13.0084\ldots\)
(f)
\(\dfrac{\sin B\hat{C}F}{8.939\ldots}=\dfrac{\sin136^{\circ}}{13.008\ldots}\)(M1)FT from (d) and (e).
\(B\hat{C}F=28.5^{\circ}\)(A1)\(28.5140\ldots^{\circ}\)
\(331.5^{\circ}\)A1\(360^{\circ}-28.514\ldots^{\circ}=331.485\ldots^{\circ}\). Accept \(331^{\circ}\) or \(332^{\circ}\).

Answers: (c) \(8.65\) km · (d) \(8.94\) km · (e) \(13.0\) km · (f) \(331.5^{\circ}\)

86AASL3-q00433.4 Radian measure, arcs and sectors Paper 2Hard10 marks
ABPQ
Diagram not to scale

Two circles have centres \(A\) and \(B\) and radii \(6\) cm and \(8\) cm respectively, with \(AB=10\) cm. The circles intersect at \(P\) and \(Q\). The shaded region is the region common to both circles.

(a)

Show that \(A\hat{P}B\) is a right angle.

(1)
(b)

Find \(P\hat{A}Q\), in radians.

(2)
(c)

Find \(P\hat{B}Q\), in radians.

(1)
(d)

Find the area of the shaded region.

(4)
(e)

Find the perimeter of the shaded region.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(AP^{2}+BP^{2}=36+64=100=AB^{2}\), so by the converse of Pythagoras’ theorem \(A\hat{P}B=\dfrac{\pi}{2}\)A1
\(A\hat{P}B\) is a right angleAG
(b)
\(\cos P\hat{A}B=\dfrac{6}{10}\) and \(P\hat{A}Q=2\,P\hat{A}B\)(M1)By symmetry about (AB).
\(1.85\)A1\(1.85459\ldots\)
(c)
\(2\arccos\dfrac{8}{10}=1.29\)A1\(1.28700\ldots\) Or \(\pi-1.85459\ldots\).
(d)
segment of circle \(A\): \(\dfrac{1}{2}(6)^{2}\left(1.854\ldots-\sin1.854\ldots\right)\)(M1)
\(16.1\)(A1)\(16.1026\ldots\)
segment of circle \(B\): \(\dfrac{1}{2}(8)^{2}\left(1.287\ldots-\sin1.287\ldots\right)\;(=10.46)\)(M1)Or sector \(A\) \(+\) sector \(B\) \(-\) kite \(APBQ\): \(33.38+41.18-48\).
\(26.6\text{ cm}^{2}\)A1\(26.5666\ldots\) FT from (b), (c).
(e)
\(6(1.854\ldots)+8(1.287\ldots)\)(M1)
\(21.4\) cmA1\(21.4235\ldots\)

Answers: (b) \(1.85\) · (c) \(1.29\) · (d) \(26.6\text{ cm}^{2}\) · (e) \(21.4\) cm

87AASL3-q00513.5 The unit circle and the ambiguous case Paper 2Hard8 marks

In triangle \(ABC\), \(AB=12\) cm, \(B\hat{A}C=40^{\circ}\) and \(BC=a\) cm.

(a)

Find the least value of \(a\) for which triangle \(ABC\) exists.

(2)
(b)

Given that \(a=9\), find the two possible values of \(A\hat{C}B\).

(3)
(c)

Hence find the difference between the areas of the two possible triangles.

(3)
Show mark scheme
WorkingMarkNotes
(a)
least \(a\) is the perpendicular distance from \(B\) to the line \(AC\): \(12\sin40^{\circ}\)(M1)Or \(\sin A\hat{C}B=1\) in the sine rule.
\(7.71\) cmA1\(7.71345\ldots\)
(b)
\(\sin A\hat{C}B=\dfrac{12\sin40^{\circ}}{9}\;(=0.857)\)(M1)
\(59.0^{\circ}\)A1\(58.9869\ldots^{\circ}\)
\(121^{\circ}\)A1\(121.013\ldots^{\circ}\); \(180^{\circ}-\) their acute angle.
(c)
\(A\hat{B}C=81.0^{\circ}\) or \(19.0^{\circ}\)(M1)FT from (b).
\(\dfrac{1}{2}(12)(9)\sin81.0^{\circ}-\dfrac{1}{2}(12)(9)\sin19.0^{\circ}\;(=53.3-17.6)\)(M1)Or using \(AC=13.8\) and \(4.56\): \(\dfrac{1}{2}(12)\sin40^{\circ}(13.83-4.56)\).
\(35.8\text{ cm}^{2}\)A1\(35.768\ldots\)

Answers: (a) \(7.71\) cm · (b) \(59.0^{\circ}\), \(121^{\circ}\) · (c) \(35.8\text{ cm}^{2}\)

88AASL3-q00553.5 The unit circle and the ambiguous case Paper 2Hard15 marks

A lighthouse \(L\) is \(9\) km from a harbour \(H\), on a bearing of \(035^{\circ}\) from \(H\). A ship leaves \(H\) and sails due north at a constant speed of \(15\) km h−1. The light from the lighthouse can be seen clearly from the ship only when the ship is within \(6.5\) km of \(L\).

(a)

Find the shortest distance between the ship’s path and \(L\).

(2)
(b)

Let \(S\) be a position of the ship at which \(SL=6.5\) km. Show that \(\sin H\hat{S}L=0.794\), correct to three significant figures.

(2)
(c)

Find the two possible values of \(H\hat{S}L\).

(3)
(d)

Hence find the two possible distances \(HS\).

(4)
(e)

Find the length of time, in minutes, for which the light can be seen clearly from the ship.

(2)
(f)

Find the bearing of \(L\) from the ship at the moment the light first becomes clearly visible.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(9\sin35^{\circ}\)(M1)
\(5.16\) kmA1\(5.16218\ldots\)
(b)
\(\dfrac{\sin H\hat{S}L}{9}=\dfrac{\sin35^{\circ}}{6.5}\)M1
\(\sin H\hat{S}L=0.794182\ldots\)A1Must see a value to more than 3 s.f.
\(\sin H\hat{S}L=0.794\)AG
(c)
recognizing the ambiguous case: \(\theta\) and \(180^{\circ}-\theta\)(M1)
\(52.6^{\circ}\)A1\(52.5781\ldots^{\circ}\)
\(127.4^{\circ}\)A1\(127.421\ldots^{\circ}\)
(d)
\(H\hat{L}S=180^{\circ}-35^{\circ}-H\hat{S}L\), giving \(92.4^{\circ}\) or \(17.6^{\circ}\)(M1)
\(\dfrac{HS}{\sin H\hat{L}S}=\dfrac{6.5}{\sin35^{\circ}}\)(M1)Or cosine rule: \(HS^{2}-18\cos35^{\circ}\,HS+(81-42.25)=0\).
\(3.42\) kmA1\(3.42245\ldots\)
\(11.3\) kmA1\(11.3222\ldots\)
(e)
\(\dfrac{11.3222\ldots-3.42245\ldots}{15}\) hours \((=0.526662\ldots)\)(M1)
\(31.6\) minutesA1\(31.5993\ldots\) Accept 31.5 from 3 s.f. values.
(f)
the light first becomes visible at \(HS=3.42\) km, where \(H\hat{S}L=127.4^{\circ}\); bearing \(=180^{\circ}-127.4^{\circ}\)(M1)
\(052.6^{\circ}\)A1Accept \(053^{\circ}\).

Answers: (a) 5.16 km · (c) \(52.6^{\circ}\), \(127.4^{\circ}\) · (d) 3.42 km, 11.3 km · (e) 31.6 min · (f) \(052.6^{\circ}\)

89AASL3-q00783.7 Circular functions and their graphs Paper 2Hard16 marks
23 m20 mboarding point

A Ferris wheel has radius \(20\) m and its centre is \(23\) m above the ground. The wheel rotates at a constant speed and completes one rotation every \(12\) minutes. A passenger boards at the lowest point of the wheel at time \(t=0\). The height of the passenger above the ground, \(h\) metres, \(t\) minutes after boarding, is modelled by

\(h(t)=a\cos(bt)+d\), where \(b\gt0\).

(a)

Write down the minimum height and the maximum height of the passenger above the ground.

(2)
(b)

Find the value of \(a\), the value of \(b\) and the value of \(d\).

(5)
(c)

Find the height of the passenger \(2.5\) minutes after boarding.

(2)
(d)

During one complete rotation, find the length of time for which the passenger is more than \(35\) m above the ground.

(4)
(e)

A second passenger boards at the lowest point exactly \(3\) minutes after the first passenger. Find the first time \(t\), where \(t\gt3\), at which the two passengers are at the same height above the ground, and find this height.

(3)
Show mark scheme
WorkingMarkNotes
(a)
minimum \(3\) mA1
maximum \(43\) mA1
(b)
\(d=23\)A1
amplitude \(=20\)(A1)
\(a=-20\)A1Negative because \(h\) is a minimum at \(t=0\).
\(\dfrac{2\pi}{b}=12\)(M1)
\(b=\dfrac{\pi}{6}\)A1Accept \(0.524\).
(c)
\(h(2.5)=-20\cos\left(\dfrac{2.5\pi}{6}\right)+23\)(M1)FT from (b).
\(17.8\) mA1\(17.8236\ldots\)
(d)
\(-20\cos\left(\dfrac{\pi t}{6}\right)+23=35\), or graph of \(h\) with \(y=35\)(M1)
\(t=4.23\)(A1)\(4.22899\ldots\)
\(t=7.77\)(A1)\(7.77100\ldots\)
\(3.54\) minutesA1\(3.54200\ldots\)
(e)
\(h(t)=h(t-3)\)(M1)Second passenger’s height is \(h(t-3)\); GDC intersection.
\(t=7.5\) minutesA1
\(37.1\) mA1\(37.1421\ldots\;(=23+10\sqrt{2})\)

Answers: (a) \(3\) m, \(43\) m · (b) \(a=-20,\ b=\dfrac{\pi}{6},\ d=23\) · (c) \(17.8\) m · (d) \(3.54\) minutes · (e) \(t=7.5\), \(37.1\) m

90AASL3-q00793.7 Circular functions and their graphs Paper 2Hard15 marks

Two buoys, \(A\) and \(B\), move up and down on the waves. Their heights, in metres, above the sea bed \(t\) seconds after a recording starts are modelled by

\(h_{A}(t)=1.4\sin(1.3t)+2.0\) and \(h_{B}(t)=0.9\cos(0.8t)+2.1\), for \(0\le t\le10\).

The graphs of \(h_{A}\) (solid) and \(h_{B}\) (dashed) are shown.

th12345678910123OAB
(a)

Write down the maximum height of buoy \(A\).

(1)
(b)

Find the period of \(h_{A}\).

(2)
(c)

Find the first time at which buoy \(A\) is at its maximum height.

(2)
(d)

Find the values of \(t\) for which the two buoys are at the same height.

(3)
(e)

Find the total time, during the 10 seconds, for which buoy \(A\) is higher than buoy \(B\).

(3)
(f)

Find the greatest vertical distance between the two buoys during the 10 seconds.

(2)
(g)

The recording continues beyond \(t=10\) and the model remains valid. Find the first time after \(t=10\) at which buoy \(B\) is at its maximum height.

(2)
Show mark scheme
WorkingMarkNotes
(a)
\(3.4\) mA1
(b)
\(\dfrac{2\pi}{1.3}\)(M1)
\(4.83\) sA1\(4.83321\ldots\)
(c)
\(1.3t=\dfrac{\pi}{2}\)(M1)Or use of GDC maximum.
\(t=1.21\) sA1\(1.20830\ldots\)
(d)
\(h_{A}(t)=h_{B}(t)\), e.g. intersections on GDC(M1)
at least three correct values from \(0.548,\ 2.61,\ 4.41,\ 6.84,\ 9.75\)A1\(0.547866\ldots,\ 2.60712\ldots,\ 4.40870\ldots,\ 6.83584\ldots,\ 9.74872\ldots\)
all five values and no othersA1
(e)
identifying intervals \(0.548\lt t\lt2.61\), \(4.41\lt t\lt6.84\), \(9.75\lt t\le10\)(M1)FT their (d).
\((2.607-0.548)+(6.836-4.409)+(10-9.749)\)(M1)
\(4.74\) sA1\(4.73767\ldots\)
(f)
maximum of \(|h_{A}(t)-h_{B}(t)|\) from GDC(M1)occurs at \(t=8.34\), where \(h_{B}\) is higher
\(2.32\) mA1\(2.31635\ldots\)
(g)
maxima of \(h_{B}\) where \(0.8t=2\pi n\); period \(\dfrac{2\pi}{0.8}=7.85\ldots\), so maxima at \(t=0,\ 7.85\ldots,\ 15.7\ldots\)(M1)
\(t=15.7\) sA1\(15.7079\ldots=5\pi\)

Answers: (a) 3.4 m · (b) 4.83 s · (c) 1.21 s · (d) 0.548, 2.61, 4.41, 6.84, 9.75 · (e) 4.74 s · (f) 2.32 m · (g) 15.7 s

91AASL3-q00873.8 Trigonometric equations Paper 2Hard8 marks

Let \(g(x)=3\sin2x-2\cos x\), for \(0\le x\le\pi\).

(a)

Solve the equation \(g(x)=1\).

(3)
(b)

Find the maximum value of \(g\).

(2)
(c)

Find the set of values of \(k\) for which the equation \(g(x)=k\) has exactly three solutions.

(3)
Show mark scheme
WorkingMarkNotes
(a)
graph of \(y=g(x)\) and \(y=1\) on GDC, or equivalent(M1)GDC in radian mode.
\(x=0.558,\ 1.30\)A1\(0.558427\ldots,\ 1.30356\ldots\)
\(x=2.98\)A1\(2.97647\ldots\) Award A0 for any extra values.
(b)
comparing the local maximum \(g(0.920)=1.68\) with the end point value \(g(\pi)=2\)(M1)
\(2\)A1Award A0 for \(1.68\) (local maximum only).
(c)
horizontal line \(y=k\) crossing the graph three times, between the local turning points(M1)
local maximum \(1.68\) and local minimum \(-1.68\)(A1)\(\pm1.68031\ldots\)
\(-1.68\lt k\lt1.68\)A1Strict inequalities required.

Answers: (a) \(0.558,\ 1.30,\ 2.98\) · (b) \(2\) · (c) \(-1.68\lt k\lt1.68\)